Cattle Health Impacts Carcass Traits

It is important for everyone involved in beef cattle production, including seedstock producers, cow-calf producers, backgrounders and stocker operators, feedlot managers, packers, retailers, feed suppliers, and veterinarians to remember that all the money distributed among the many participants is generated by the sale of beef to consumers. While it is true that carcass traits and beef product attributes are largely influenced by the genetic decisions of seedstock and commercial cow-calf producers and the feeding decisions of feedlot managers and nutritionists, the animal health decisions made by producers and veterinarians throughout the production chain also play a role. A number of studies have indicated that muscling, marbling, and tenderness all can be negatively impacted by cattle health problems.  

Studies of consumer preferences have indicated that attributes such as flavor, tenderness, marbling, and texture are important when evaluating the eating experience when consuming beef cuts. These consumer expectations are important when considering the impact of animal health because pneumonia and other common cattle diseases have the potential to affect not only carcass weight, but also the amount, location, and ratio of muscle, fat, and water.  

Bovine respiratory disease (pneumonia) is the most important cause of illness and death in feedlot cattle with digestive diseases such as acidosis and bloat also being important. Several studies have shown that cattle that experienced respiratory disease had lighter hot carcass weight, lower dressing percent, less internal fat, and lower marbling scores as well as less external fat and smaller ribeye area than cattle without respiratory disease. Scientists don’t have a clear picture of how disease impacts carcass traits, but probably a combination of changes in hormones such as insulin, growth hormone, and other signals that direct the growth of muscle and the deposition of fat are involved.  In addition, just the fact that cattle are off-feed while they are sick may impact the pattern of muscle growth and fat deposition.  

The negative effects of disease on carcass traits may not be confined to the time cattle are in a feed yard. As we learn more about muscle growth and fat deposition, it appears that stress, disease, or poor nutrition even early in life can have consequences on feedlot and carcass performance. This understanding makes a life-long health and nutrition plan to minimize disease risk and ensure optimum growth from birth to slaughter important for efficient production of a desirable beef product. Beef producers should work with veterinarians to optimize sanitation, nutrition, immunization, and biosecurity to reduce the risk of disease. In addition, because the negative effects on growth and carcass traits appear to be more severe in animals with prolonged or multiple episodes of sickness compared to animals that become sick for a short period of time and then recover, knowledge and ability to accurately identify sick animals and to treat them in a timely manner also becomes increasingly important.  

Life-long cattle health starts with the cow being in good body condition and receiving all necessary nutrients throughout pregnancy and then giving birth without calving difficultly in a clean environment. If the calf is born healthy and able to quickly stand and suckle and that calf is not exposed to mud and manure, it is likely to avoid the risk of scours and pneumonia during the time period from birth to weaning. Adequate forage availability for both the cow and calf until weaning is essential to maintain optimum health and to ensure that the calf has good post-weaning growth and health.  

Effective vaccines are available for a number of important disease-causing germs including the bacteria that cause blackleg and related diseases, and the viruses and bacteria that contribute to bovine respiratory disease. Both internal parasites (worms) and external parasites (flies, ticks, and lice) can cause significant disease in calves; and proper use and timing of deworming and external parasite treatments greatly aids in cattle health and well-being. The time period around weaning is a period of high risk for respiratory disease and other diseases. Implementation of well-designed preconditioning programs that utilize low-stress weaning, vaccinations, parasite control, and acclimation to post-weaning diets and feeding and watering equipment is an excellent disease control strategy.  

Carcass premiums and pricing on carcass merit grids has caused the veterinary profession to re-evaluate the cost of cattle diseases. Historically, veterinarians and beef producers have considered the cost of disease to be confined to death loss, treatment cost, decreased feed efficiency, and reduced live weight. However, because many cattle are now sold on a carcass merit basis, disease has the potential to affect profitability not only through treatment costs, death loss, and reduced weight, but also the amount, location, and ratio of muscle, fat, and water and the ultimate desirability of the final beef product.   

Ensuring that consumers have a satisfying experience every time they eat beef requires that all the participants in the beef production chain do their part to improve and protect the attributes of flavor, tenderness, marbling, and texture. In addition to the significant impacts that genetics and nutrition play on carcass and product traits, cattle health also has an important role; and a plan to optimize health from birth to slaughter is an important component of providing a high-quality beef product.  

Preventing Spontaneous Abortions in the Herd

Both beef producers and veterinarians express frustration when a cow that is identified as pregnant later aborts the fetus during mid-pregnancy. Because reproduction is complex and a number of germs, toxins, and genetic problems can lead to pregnancy loss, veterinarians recognize that losing about 1% to 2% of pregnancies between the time of pregnancy diagnosis and calving is probably unavoidable. The goal of many aspects of cowherd health programs including nutritional management, biosecurity, and vaccination is to reduce the risk of abortion and particularly to prevent situations when more than 5% of the herd aborts.  

Veterinarians approach abortion management by focusing on two related activities: diagnosing the causes of abortion and preventing abortions from occurring. Cowherd abortions can occur either sporadically or in larger outbreaks. Sporadic abortion losses are considered to occur when less than 2% of the entire herd aborts and no group of cows as described by age, pasture, or other risk-group has greater losses than other groups. When investigating sporadic abortion losses, it may not be justified to spend a great deal of resources to attempt to identify the causes; but if a larger abortion outbreak is occurring, a thorough investigation to discover the factors that are contributing to the losses is necessary to identify changes in herd management to prevent similar outbreaks in future years. The problem that both cattle producers and veterinarians face when a few cows abort is to determine if an abortion storm is beginning or if the few identified abortions are the only ones the herd will experience.   

When the first abortion is identified by finding an aborted fetus or seeing signs of abortion in a cow previously diagnosed as pregnant (such as a retained placenta or return to heat) the veterinarian may want to collect samples from the fetus, the cow, and the placenta and to record information about the aborting cow such as her age, the date the abortion was discovered, the estimated fetal age, and the identification of the pastures she has been located during pregnancy. The samples may be sent to a diagnostic laboratory or the veterinarian may suggest that the samples be saved and only submitted for laboratory investigation if more abortions occur. Some causes of abortion are fairly easily identified by a diagnostic laboratory if the samples are fresh, but other abortion-causing germs and toxins are difficult to confirm. Many of the causes of abortion work fairly slowly, so that there are many days or weeks between the time that a cow is exposed to the cause of the abortion and the actual loss of the fetus. In these situations, the diagnostic laboratory may not be able to identify an abortion cause that is no longer present in the fetus or the cow. In other situations, the germs or toxins that cause abortion affect the cow but may not actually invade the fetus making samples taken from the fetus of no help for making a diagnosis. It is important to realize that even in situations in which the diagnostic laboratory does not identify a cause for the abortion, important information is gained by removing certain easily-diagnosed factors from the list of likely causes.  

Veterinarians and cattle producers work together to create management plans that help to prevent abortions by targeting the most likely causes that can be effectively controlled. Biosecurity plans that rely on diagnostic testing and herd segregation to minimize the risk and effect of trichomoniasis (Trich) and Bovine Viral Diarrhea (BVD) should be created to meet each herd’s specific level of risk. Online tools named Trich CONSULT (https://ksubci.org/trich-consult/) and BVD CONSULT (https://ksubci.org/bvdbovine-viral-diarrhea-control-consult/) are useful to create herd-specific biosecurity plans for these diseases. Vaccination protocols to increase herd immunity against infectious bovine rhinotracheitis (IBR), bovine viral diarrhea (BVD), leptospirosis, and campylobacteriosis (vibriosis) should be implemented with an emphasis on building immunity in herd replacements as well as maintaining immunity in mature adults.  Other diseases such as neosporosis, foothills abortion, and pine needle abortion are difficult or impossible to control with diagnostic testing, herd segregation, or vaccination. Some abortion risks must be addressed by having good feed security while other require carefully planning the best age and stage of pregnancy to expose cattle to pastures where abortions are likely to be initiated when the cause of abortion is either plants or diseases carried by ticks or other insects. Effective control measures have not been identified for some causes of abortion, and the best management in these situations is to work toward good overall herd health and to keep the accumulated level of abortion risk low.  

While it is impossible to prevent all abortions, a well-planned strategy designed by a veterinarian and cattle producer working together to target the most important risks for each specific herd provides reasonable protection against devastating pregnancy losses. The best herd health plan to prevent abortion losses is the plan that optimizes nutrition, biosecurity, vaccination protocols, and grazing management for your herd. 

Planning Winter Supplementation

For most of the U.S. and Canada, winter feed is one of the greatest costs of cow-calf production. The base ingredient in winter rations is usually standing dormant forage or hay. Heifers, fist-calf heifers, and thin cows that need to gain body condition often need more energy than can be supplied by dormant forage or hay alone. Therefore, many situations require that heifers and cows be fed supplemental protein, energy, or both, depending on the nutrient makeup of the base-forage. Understanding the interaction between starch, fiber, and protein in the cows’ rumen allows producers to determine the most appropriate winter supplement. 

Many different types of bacteria and other microorganisms in the rumen convert forage and supplements into nutrients needed to maintain or increase a cow’s body weight. What makes cattle and other ruminant animals so important to the earth’s ecosystem is that a great deal of the energy stored on the planet is stored in the fibrous parts of plants that cannot be used by non-ruminants (humans, birds, and most animals). In addition, it is important to recognize that even cattle and other ruminants can only use the energy stored in the cell walls of plants when the rumen bacteria have enough protein and other nutrients to actively breakdown the fibrous plant parts. Fiber-digesting bacteria, which are important for digesting forage, are relatively slow growing and are easily killed if the rumen becomes acidic. In contrast, starch-digesting bacteria are important to grain-fed ruminants, and reproduce rapidly when starch is available. Starch-digesting bacteria have a much greater tolerance for increased acid in the rumen than do fiber-digesting bacteria. 

Changes in diet will change which types of bacteria in the rumen are most plentiful. The types of supplements that cattlemen choose to feed will affect the types of bacteria that dominate the rumen which will have an effect on how well cows can convert the base forage into body weight. Some supplements will increase the digestibility of the base forage, some will not greatly affect the base forage digestibility, and some will actually decrease the ability of cows to convert forage into body weight.  

Cattle fed a forage-based diet (grazing or hay) that is deficient in protein (<7% Crude Protein) will benefit by being fed a protein-dense supplement to supply the necessary amount required for reproduction by fiber-digesting bacteria. By increasing the number of fiber-digesting bacteria in the rumen, forage digestibility is increased, the cows’ eat more forage, and the energy yield from the diet is improved.  

However, producers should realize that if the base forage has adequate protein content, additional protein will not improve digestibility or energy yield. A typical 1,200-pound cow of average producing ability will need only about 1.7 pounds of crude protein during the middle part of gestation. Feeding a roughage of fair quality (8 to 10% crude protein) during this period should meet both energy and protein requirements, and feeding a protein supplement is not necessary. In contrast, after a cow calves, her requirement for protein increases greatly. A 1,200-pound cow producing 20 pounds of milk requires 3 pounds of crude protein daily and a forage that was adequate in mid-gestation may be very protein deficient for late gestation and early lactation. 

Because of the competition that takes place in the rumen between starch-digesting and fiber-digesting bacteria, it is important to limit the amount of grain in the diet of cows grazing standing dormant forage or eating hay. If cows are eating forage of moderate quality (protein content and digestibility), supplementing with too much grain, which is high in starch, will actually decrease the digestibility and available energy from the forage even further. This decrease is due to a shift in the population of rumen bacteria away from a population dominated by fiber-digesters, to a population dominated by starch-digesters. Remember, the starch-digesting bacteria can reproduce rapidly when starch is available, and during rapid growth, starch-digesting bacteria produce increasing levels of lactic acid, which will kill many fiber-digesting bacteria. With fewer fiber-digesting bacteria available, forage digestibility is decreased and energy yield from the forage is reduced.  

Because corn and other grains are readily available and often are price-competitive with other sources of energy, producers can use these feeds up to the level where they have a negative effect on fiber digestion. The cut-off for starch supplementation of low-quality forages calculates to be about 0.28% of the cows’ bodyweight for corn dry matter (3.5-4.0 lbs. of corn as-fed for a 1,200-pound cow). For moderate weight gain, a simple diet of forage and less than 3.5-4.0 pounds corn will often be sufficient.  

In situations when the base forage has adequate protein, if more weight gain is required than can be met with a starch-based feed such as corn without a negative effect on forage intake and digestibility, producers can choose to use a fiber-based feed that has higher energy content than the base forage. Many by-product feeds provide energy in the form of highly digestible fiber; because the energy is in the same form as that in the forage, high levels can be fed without harming the fiber-digesting bacteria in the rumen or decreasing forage digestibility. By-product feeds that provide energy in the form of highly digestible fiber include: corn gluten feed, distillers grains, soybean hulls, and wheat middlings.  

Working with your veterinarian, nutritionist, Extension specialist, or other ration-planning resource to help you properly select the type and amount of supplement that compliments your base forage will ensure that your cows maintain adequate body condition and that winter feeding bills are optimized. 

Weaning Beef Calves

The times in a beef animal’s life that it is most at risk for disease or death are at birth and the first few weeks of life, and again for the first few weeks after weaning. This is particularly true if newly weaned cattle are commingled with other cattle and shipped to a new location. There are several strategies that ranchers and veterinarians can utilize to reduce risk of disease associated with the changes that accompany weaning.  

At weaning, milk is removed a calf’s diet. For many beef calves, this is a relatively minor change in diet composition because by the time calves are weaned at six months of age or older, they are already consuming a majority of their nutrients from grazing and their dam’s milk production is declining rapidly. But a change in diet is not the only change associated with weaning, in that the social interaction between the dam and calf is also changed.  

The reason that weaning is associated with increased risk for disease in calves is that stress strongly suppresses the immune system, making the calf susceptible to the germs and parasites that are commonly found in nature. Sudden diet change, separation from dams, castration, vaccinations, and moving to a new location are all potential sources of stress for weaned calves.  

There are many different ways to reduce the stress associated with weaning-age calf management. Every rancher should look at his/her own facilities and marketing plan to come up with the best strategy for their operation. Basically, optimum weaning strategies are planned to avoid having multiple additional stressors happen at the same time as weaning, and to reduce the stress of weaning itself.  

Near the time of weaning, calves are often moved to new environments and commingled with new cattle from the same ranch or from multiple ranches. Because of these changes, calves are likely to contact germs that are new to them. A vaccination strategy to prepare the immune system of calves ahead of exposure to common disease-causing germs is helpful to decrease the risk of disease. No vaccine is able to provide complete protection from disease, but vaccines that are given at times of significant stress are much less likely to provide adequate disease protection compared to vaccines given to calves that are not coping with other stressors.  

Pre-conditioning programs have been developed to move stressful management processes such as castration, dehorning, and vaccination earlier in a calf’s life to reduce any adverse health impacts of those procedures, and to move these stressors to times away from weaning. In addition, if grain or grain by-products are part of the post-weaning diet, preconditioning programs usually recommend or require that for two to three weeks before weaning, calves are exposed to the type of diet they will be expected to consume after weaning. The post-weaning diet must ensure that calves receive adequate energy, protein, and trace nutrients to support a strong immune system and to maintain or increase growth rate. 

The timing of weaning is affected by many factors including the ranch’s calf marketing strategy and the availability of adequate forage to maintain cow health and productivity. If drought conditions reduce available forage so that cow body condition and calf growth are meaningfully affected, calves can be weaned at an early age to remove calf-grazing and lactation pressures on forage intake by the herd. Beef calves can be successfully weaned any time after they develop a functioning rumen at a few weeks of age.  

There are several broad categories of weaning strategies such as: fence-line weaning in the current pasture where cows are kept in view but not in contact with the calves, pasture-weaning in the current pasture with the cows moved completely out of contact, and weaning to a drylot with cow herd contact. 

A few research studies have compared fence-line weaning where calves can see their dams but are separated by a fence, to other strategies that involved weaning on pasture with the dams completely removed or weaning into a dry lot with no contact with cows. These studies generally show improvements in calf behavior such as bawling and pacing for the first few days after weaning for fence-line weaned calves. Some, but not all studies, show differences in disease risk and weight gain based on the weaning strategy used. Management practices to decrease the stress associated with weaning should be investigated and ranch-specific strategies that optimize health, welfare, and economic considerations should be implemented. 

If calves are weaned into a new environment such as a drylot, it is important that they have access to plenty of fresh water and that they know how to find and drink from the water source. Calves that have only been provided water from streams or ponds may not recognize tanks and controlled-flow waterers. Feed bunks, hay rings, and water sources must all be accessible to calves. Many of these feeding devices are designed for yearlings or adults and may be difficult for calves to use. Many newly weaned calves will not aggressively approach crowded feed bunks; therefore it is recommended that feed be spread out over 18 to 22 inches of bunk space per calf.  

No matter what strategy is used, weather should be an important consideration when choosing the day of weaning. Although not perfect, a multi-day weather forecast can help you avoid adding weather stress to the other stresses of weaning. The greatest risk of disease for weaning-age calves is during the first three weeks after they are separated from their dams. During this time, the calves should be observed frequently (usually twice a day) for signs of respiratory disease, diarrhea, lameness, or failure to gain weight. Work closely with your veterinarian to develop a treatment plan for the types of problems you may encounter.  

Although weaning is associated with increased disease risk, a herd-specific plan to implement management practices such as castration, dehorning, and vaccination while calves are still with their dams; and then using weather reports and low-stress weaning strategies to minimize the stress of weaning, you can protect calf health and growth during this critical time. Your veterinarian, extension agent, university personnel, and neighbors may have ideas that you can implement to improve weaning on your farm or ranch. 

Treatment Protocols

In many food animal production systems, treatment protocols are an important component of maintaining herd health.  A treatment protocol is the veterinarian’s instruction for disease management and can be developed within the context of a veterinary-client-patient relationship.  A well-designed treatment protocol should include: 

  • Case definition  
    • Signs/symptoms that indicate the animal has met the requirements for receiving treatment 
  • Drug regimen – administration instructions that specify: 
    • The drug 
    • Dose to be administered 
    • Route of drug administration 
    • Site of drug administration (drug label or BQA guidelines) 
    • Maximum volume of drug administered per injection site 
    • Needle size 
    • Frequency of administration (examples: single injection or every 12 hrs) 
    • Treatment duration 
  • Treatment success/failure criteria 
    • Indicators that the animal requires additional treatment 
  • Secondary/additional treatments 
    • Drug regimen details as above 
  • Instructions for disposition of treated animals 
    • Withdrawal time for meat (and milk if used in lactating dairy cows) 
    • Salvage slaughter vs. euthanasia for treatment failures 

The treatment protocol should be agreed upon by farm personnel and the veterinarian.  By sticking to the protocol, it ensures the best treatment outcomes and allows for evaluation of treatment effectiveness.  While a change in protocol may be necessary in rare cases, this should only be done after consultation with your veterinarian. 

Equipment

Beef cattle producers typically own several different types of animal health equipment. A few important considerations are: obtaining good quality equipment, focusing on cleanliness, and making sure that all equipment is well-maintained.  Some common animal health equipment likely to be found on many ranches includes: portable squeeze chutes and handling facilities, scales to collect body weight, warming crates for calves born in cold conditions, AI (artificial insemination) supplies, calving chains and calf jacks for use in cases of calving difficulty, ear tag pliers, tattoo pliers, castration and dehorning tools, and syringes and needles. 

While it is important to search for value when purchasing animal health equipment, equipment that breaks easily or that won’t reliably perform its function is never a bargain no matter what the purchase price. If high-priced equipment is needed only rarely, finding a source that can lease it on an as-needed basis may be preferable to purchasing. Buying needed supplies and equipment from local sources has the advantages of convenience and knowing who will stand behind the equipment they sell. Online suppliers and large outlets have the advantage of a large inventory and wide selection. The best source for your equipment needs will depend on your geographic area and your priorities.  

Keeping equipment clean is almost always good advice, but cleanliness for animal health equipment is especially important. Many types of equipment will come with manufacturers’ recommendations for cleaning and it is always important to follow these directions. In general, washing with hot water, soap, and appropriate brushes or other utensils is usually a good place to start. For some animal health equipment, it is recommended to use a disinfectant to remove germs once the item is clean of all dirt and other debris. It is important to recognize that disinfectants wont’ work in the presence of dirt, manure, or blood so a good cleaning is always the first step. Because cleaning and disinfecting detergents can easily destroy the ability of vaccines to work effectively, thoroughly cleaning reusable syringes followed by boiling them in water will kill any germs on the equipment without leaving a residue that can harm vaccines. Needles should not be cleaned and re-used – instead use disposable needles.  Always clean syringes between uses; it is important to not use a syringe for one product followed by another product without a thorough cleaning in between uses.  

Previously used needles should never be used to withdraw vaccine from the bottle. This should only be done with a brand new needle to prevent contaminating the contents of the bottle. For rehydrating the freeze-dried portion of a modified live vaccine with the provided liquid, ideally, a double-sided transfer needle should be used. If a transfer needle is not available, you should use a new needle and syringe.  

There are diseases of cattle that can be spread by very small amounts of blood – even the trace of blood left on tattoo pliers, tagging instruments, castrating knives, and injection needles. To help prevent the spread of anaplasmosis and bovine leukosis, instruments that contact blood should be rinsed or wiped off between uses to remove all traces of blood.  

Maintenance and service instructions provided with new equipment should be followed to ensure that your equipment is ready to use when you need it. All equipment should be examined closely for signs of wear or problems than you can address, and to recognize when you need to send equipment to an expert for repair. Some equipment needs routine lubrication or sharpening and having all the materials you need to keep you equipment in good working order is important. For items that may break during routine use, having at least one back-up is probably a good idea.  

Cleaning and maintaining animal health equipment are important considerations when implementing BQA (Beef Quality Assurance) on your cattle operation. This includes proper care and use of syringes and needles to prevent injection site problems, keeping animal handling equipment in good working condition to prevent bruising or injury, and having clean, reliable equipment for use when assisting difficult births or dealing with other health emergencies to ensure good animal care and welfare.  

Animal health equipment is one of many considerations when providing good care for your cattle. Taking a little time to consider what equipment you need, how you will keep it clean, and the best methods to make sure it is well-maintained will serve you well as you go about the daily tasks of caring for your herd.  

Cattle Lameness

Lameness in cows, bulls, and replacement heifers is a common problem confronting cattlemen. In most situations, the problem is occurring in the foot, with occasional lesions in the shoulders, hips, knees, and other joints. Problems in the foot can be due to injury, infections, malformations of the foot, or a combination of these factors.  

One of the most common problems of cattle feet is an infection of the skin and soft tissue above the hoof known as footrot. The bacteria that causes footrot is present in soil and is very common in cattle pens. In order for the bacteria to invade the foot, a break in the skin must occur first. Injury that allows infection may be due to rocks or rough ground, crop residue stubble, or extreme dryness. Wet and muddy areas can also be a problem in that prolonged exposure to wet ground can cause the skin to become soft and more easily injured. All lame cattle should be confined in a squeeze chute where the foot can be lifted and carefully examined to make an accurate diagnosis. It is very easy to mistake a puncture wound or other problem for footrot. If identified early in the course of the disease, most cattle will respond to treatment with antibiotics with complete recovery. If the infection has had longer to invade nearby joints, recovery is less likely. Prevention of outbreaks of footrot is primarily directed toward maintaining clean pens and designing watering and feeding areas to prevent the build up mud. Occasional, individual cases of footrot are probably unavoidable and these sporadic cases should be identified and treated as soon as possible. Use of feed additives such as iodine and antibiotics have not consistently shown to be beneficial for preventing footrot.  

A disease called hairy heel warts or digital dermatitis can also occur on the feet of cattle. Most commonly, a painful raw area that can look like a wart and may have long hair-like growths is identified directly behind the heels, but the area between the toes can also be affected. This disease is common in dairy cattle herds and although it is rare in cow-calf herds, it does occur in feedlot cattle and beef cattle that are housed in a drylot or on concrete. The current theory is that two or more germs work together to cause the disease and that these organisms thrive in manure-contaminated water. Housing that minimizes the time spent standing in water is the best prevention. Footbaths with antibiotics are used for treatment in dairies.   

Lameness in cattle can also be caused by infections in and around joints by bacteria that have traveled from other infections in the body. Mycoplasma bovis is an organism that is found in the lungs of some cattle with prolonged cases of pneumonia. This organism can travel through the bloodstream and infect joints and tendons causing severe lameness. Many antibiotics do not kill the organism and treatment of cattle with lameness due to Mycoplasma bovis is often not successful.  

Lameness can be caused by injuries to the foot or leg. Puncture wounds from nails, glass, or sharp pieces of metal can cause damage to the hoof itself or to the soft tissue around the hoof. Puncture wounds are often accompanied by a great deal of swelling and may appear similar to footrot. Damaged or poorly maintained loading chutes, alleys, or fences with sharp protrusions can also injure feet and legs.  

Toe abscess are most common in calves in confinement, particularly where sorting pens are abrasive and the cattle have soft hooves. Acidosis may also be a factor, and excitable behavior is considered to increase the risk that cattle may scramble on the concrete of the treatment or processing areas causing abrasions of their toes, which allows infections to occur. Toe abscesses are treated by nipping off the tip of the toe to allow drainage, administering antibiotics, and placing the cattle in areas with clean, solid footing. Sole abscesses are less common, but more difficult to treat than toe abscesses. The sole must be trimmed and the abscess opened to allow drainage and a wooden block is glued to the opposite toe to keep the affected toe from bearing weight. Sole abscesses are most common on the inside toes of the front legs and the outside toes of the back legs and may be related to incidences of acidosis. Laminitis is the foot problem most commonly associated with acidosis. In most cases of laminitis, the cattle on are on a high-concentrate diets or on stalk fields with a lot of residual grain. Severe cases of laminitis in cowherds will result in the animal being culled. 

Structural soundness occurs in varying degrees and structural problems can cause lameness. Pigeon toes, long toes, and straight hocks are examples of some of the more common structural problems. Corkscrew hoof is a genetic problem and any animal with the condition should be culled from the breeding herd. The hind leg should have an acceptable set to the hock as viewed from the side. The range of acceptability is 120° to 155° with the ideal of 140°. The post-legged condition, when rear legs have a greater than 155° set to the hock, is a fairly common and serious skeletal defect in beef cattle. Exceptionally straight hind legs are often associated with steep pasterns and straight shoulders. The bow-legged condition of hind legs is associated with a narrow placement of the feet and a disproportionate amount of weight on the outside claw, which can lead to lameness. When evaluating front limb structure, cattle should have an adequate slope to the shoulder (45°-50°) and the legs should be acceptably straight when viewed from the side and front. Front legs that bow inward at the knees up to 10° are considered acceptable but, knees that bow outward even slightly are unacceptable.  

Cattle lameness due to footrot can usually be corrected with timely and appropriate therapy. Other infectious problems such as digital dermatitis and toe or sole abscesses are more difficult to manage, but many affected cattle can be successfully treated. Malformations in the legs or toes often have a genetic component and although treatment such as corrective foot trimming can make the cattle more comfortable, no long-term cure is available. Whenever cattle become lame, it is almost always a good idea to confine the affected animal in a squeeze chute or tilt-table that allows thorough examination so that an accurate diagnosis can be make and appropriate treatment initiated.  

Cow Herd Mineral Supplementation

When I think about meeting the nutritional needs of beef cow-calf herds, I fist focus on the ability of the base forage to meet the energy and protein needs of the various groups of cattle on the ranch that differ by age and lactation status. But another aspect of nutrition that must also be considered is the mineral content of the diet. The minerals available from grazed and harvested forages and feed depend greatly on the soil on which it is grown as well as the type of plant being consumed. Because of the importance that soil plays in the availability of many minerals, supplementation needs can vary greatly across North America. In addition, mineral needs (particularly calcium and phosphorus) will increase somewhat in late gestation and to a greater extent during lactation compared to non-lactating cattle (heifers, dry cows, bulls). 

Several minerals are necessary in beef cattle diets to maintain optimum health, reproduction, and growth. Minerals needed in relatively large amounts are described as major or macro minerals while minerals needed in small amounts are usually called micro or trace minerals. The major minerals that most commonly need to be supplemented in beef cattle diets are sodium (salt), calcium, and phosphorus, while magnesium and potassium are major minerals that require supplementation under certain circumstances. The six trace minerals that may be deficient in forage-based diets are copper, cobalt, iodine, selenium, zinc and manganese.

The mineral needed in the greatest amount in beef diets is salt (sodium chloride). Because salt is deficient in most natural feeds, it should be supplemented in all situations. The level of salt needed can vary depending on the diet, type of cattle, and environmental conditions, but a general rule is to supply 1 to 2 oz per day. 

Calcium and phosphorus are often considered together. Calcium content of grass decreases somewhat as forage matures and becomes dormant but often maintains levels that supply dietary needs throughout the year. Phosphorus, however, is leached out of dormant forage, so that by mid-winter levels are much lower than while forages are growing. Grains and many by-product feeds used to supplement cows on dormant forage such as wheat middlings, soybean products, distillers grains, and corn gluten feed have high phosphorus content that will likely provide sufficient levels in the diet. 

The Coastal Plain of Texas and other portions of the Gulf Coast, the Sandhills of Nebraska, Montana, as well as portions of Minnesota, North Dakota, and areas in numerous other states have phosphorus-deficient soils and diet supplementation should be a priority. In many other parts of the country, phosphorus deficiencies are seldom identified and phosphorus supplementation is not needed or can be strategically planned for period of high demand (late gestation and early lactation). 

Deficiency of magnesium is identified as a condition known as grass tetany. Observed most frequently in the early spring, grass tetany results from the consumption of lush forage, which has low levels of magnesium and sodium and has an excess of potassium. In addition to plant factors, grass tetany is associated with late pregnancy and early lactation due to the movement of calcium, phosphorus, and magnesium out of blood circulation and into the udder for milk production. During periods when grass tetany is a danger, a mineral mix with at least 18% magnesium needs to be offered. Because cattle do not like the taste of magnesium oxide, dry molasses or other flavor enhancers should be added to the mineral mix.

Minerals needed in small amounts are called trace minerals, and in most situations requirements are met with grazed forages or supplemental feedstuffs. But deficiencies or imbalances of trace minerals can occur when cattle grazing on some soil types consume plants that are either deficient in some important trace minerals or have excessive amounts of minerals that will tie-up or prevent the proper utilization of other minerals. For example, iron, molybdenum and other minerals, nitrate, sulfate, protein, and plant estrogens are known to reduce copper utilization. The first priority in trace mineral nutrition is to reduce the intake of antagonists in order to minimize the amount of supplemental mineral required. This may be accomplished by changing water sources, rotating pastures so that animals are not on pastures with high levels of antagonists for long periods of time, or changing harvested forage sources.  

Commercial mineral supplements are widely available and will meet the needs of most classes of cattle. The amount of each mineral provided by commercial products must be printed on the label. In some situations (due to concentrate feeds used and soil type), no commercial supplement is available to perfectly meet a herd’s mineral needs. In these situations, custom-mixes can be created. In this circumstance, the supplier of the supplement will work with the producer to provide the proper level of minerals based on analysis of the animal’s diet. 

Salt and other minerals can be delivered to cattle in several forms. If possible, minerals can be mixed into hand-fed protein or energy supplements so that all cattle are more likely to receive their allotted amount. But, if no supplement is being fed or if it is difficult or impossible to add minerals to the supplement, salt/mineral can be offered free-choice in a loose granular form or as a block or tub (or other solid or semi-solid form). All free-choice methods of mineral delivery will likely result in some cattle consuming far more and others far less than the desired amount. It has been reported that supplying salt/mineral in a loose form results in the highest intake, but because of loss to wind and weather or because of other convenience factors, a solid or semi-solid form may be more appropriate in some situations. Many commercial protein supplements – whether in a pellet, cake, tub or liquid form, have salt and other minerals added so that additional mineral supplementation is not needed. 

Because cows do not have the nutritional wisdom to consume the proper amount of free-choice mineral supplement to meet their dietary requirement or to avoid toxicity, it is important to monitor mineral intake. Determining the amount of mineral consumed over several days is necessary in order to know the herd’s average consumption. If consumption is too low, feed intake enhancers such as dry molasses, wheat mids, cottonseed meal or flavoring may be added. If consumption is too high, salt may be used to limit intake to desired levels. 

Being a Good Neighbor from a Cattle Health Standpoint

Being a good neighbor (and having good neighbors) is an important consideration when planning your overall herd health strategy. The impact that neighboring cattle can have on the health of your herd depends on the level of contact, the specific disease in question, and the timing of contact between herds. Nearby herds that can impact your herd’s health can range from herds comingled with yours for grazing purposes, to herds with fence-line contact with your herd, to herds with no direct contact with your cattle but within a distance that escaped cattle, wildlife, humans, and air- and water-flow could move disease-causing agents between herds. For most disease risks, more frequent and long-lasting exposure between herds carries greater risk than very occasional or short-term contact. However, even short-term contact between herds can lead to serious health problems if the exposure occurs during a time in pregnancy when either the dam or fetus is particularly vulnerable, or at an animal-age or time of year when a particular disease causes the most problems.  

Viruses, bacteria, and other microorganisms can cause disease when the dose of disease-causing agents overwhelms the ability of cattle to fight them. Cattle herds can fail to build good immunity to some diseases either because of certain characteristics of the germs themselves or because some disease-causing germs are rarely found in herds and herds are unlikely to build long-term immunity against germs they don’t contact. In these situations, even a small exposure may lead to many cattle becoming sick, aborting their fetuses, or having other negative consequences; and contact between herds increases this risk. In contrast, some disease-causing agents are so common in cattle populations that it is unlikely that any one herd is completely free of the organism – so contact between herds does not greatly increase the risk of many common diseases. 

The germs that cause trichomoniasis (Trich) and bovine viral diarrhea (BVD) are examples whereby most herds are susceptible to major disease problems if exposed to cattle that carry these germs. One of the common ways to expose a herd to these diseases is by contact with neighboring herds. Other diseases such as anaplasmosis are common in many parts of the country but rare in other parts – therefore contact with neighboring herds can increase the risk for these diseases in some areas but not in other areas. And diseases such as bovine leukosis, neosporosis, and the agents that cause bovine respiratory disease and calf scours are so common that contact between herds would rarely increase the disease risk in herds that are already infected.

It is important to work with your veterinarian to devise an appropriate plan to keep your herd from being exposed to cattle that carry Trich and BVD organisms. You should also work with your veterinarian to implement a strategy to limit the negative effects of bovine respiratory disease, calf scours, and other common diseases even though you will not be able to eliminate or keep the germs associated with these diseases from your herd. 

A few diseases can be passed even after cattle have died; therefore, proper carcass disposal to prevent direct contact with other cattle, spread of organisms by scavengers such as coyotes and birds, and contamination of water or soil that other animals may contact is necessary to be a good neighbor. Your veterinarian, Extension agent, or local regulatory contacts can provide you with information about proper carcass disposal. 

Being a good neighbor also means that you control flies as well as toxic plants and weeds that can move from one cattle operation to another. In many situations, pest control can only be effective if all the agriculture operations in the area implement control measures; and all operations benefit from the efforts of others in the area. But even as pesticides and other chemicals intended for use on plants and animals can be important weapons to control disease and improve animal health, they also pose a toxic risk if they are not applied or disposed of properly. It is important that everyone using farm chemicals is properly trained on how chemicals should be applied to animals, plants, and premises, and also how they should be stored so that animals are not accidentally exposed to concentrated, toxic doses, and how to safely dispose of any residues and the empty containers. 

In summary, being a good neighbor from an animal health perspective involves having good pasture management, animal husbandry, and animal health skills. Specifically, good neighbors use effective pest control, maintain good fences to limit unintended cross-fence exposure, and work with a veterinarian to implement vaccination and biosecurity plans for diseases that can move from one herd to another to provide protection not only to your own herd, but to decrease disease risk for other herds in the area. 

Cattle Handling Facilities

Many animal health interventions require that cattle be gathered to a handling facility that allows individual animals to be separated from the rest of the herd and confined in a squeeze chute. In situations where all the cattle in a pasture or pen are healthy and are going to be handled to give animal health products such as vaccines or parasite control, or to monitor body condition score or pregnancy status, the facilities have to be large enough to accommodate all the cattle in the group. When a few cattle from the herd need to be examined or treated for disease, the facilities have to allow safe and efficient separation of the desired animals from the rest of the herd and then adequate restraint in a squeeze chute to allow access for close inspection of areas on the animal’s body that require treatment. Cattle should be able to be moved from the pasture or pen to the working area and through the handling facilities with a minimum of stress to both the cattle and producer.

Because cattle are prey animals and can easily react to contact with people and dogs with a ‘fight or flight’ response, it is important to prevent cattle from becoming agitated when being handled. Cattle are herd animals and tend to become fearful when left alone. Strategies to minimize fear include moving cattle slowly and quietly and always moving cattle in small groups. Do not use dogs to move cattle in confinement, and minimize the use of electric cattle prods. Because cattle balk at moving or flapping objects, the crowding pens, single-file alley, and loading ramp should be monitored to make sure that nothing within the line of sight could cause them to react. As cattle are moved from the pasture or pen toward the working facility, do not over-crowd them. Never fill the crowd pen – rather only add enough cattle to be about one-half of capacity, and then do not “crush” the cattle with the crowd gate to force them into the single-file alley. The crowd gate is used to follow the cattle, not to shove up against them. Cattle should have room to move around in the crowd pen with the only visible route of escape being the alley. If a lone animal refuses to move, release it and bring it back with another group.

Cattle have excellent wide-angle vision (in excess of 300 degrees) due to the wide position of their eyes and can see behind themselves without turning their heads. And while cattle do have depth perception, they have difficulty seeing the size and shape of objects at ground level when their heads are raised. To see depth near the ground, cattle have to lower their head, perhaps explaining why cattle balk at distractions at ground level. Because contrasting patterns caused by fence or panel shadows will cause balking, lighting considerations are important for moving cattle smoothly through handling facilities. In addition, cattle in a dark area will move towards a dim light but they tend to balk if they have to look into the sun or a bright light. Because cattle may refuse to enter a dark, indoor working alley from a bright, outside crowding pen, it may be necessary to extend the alley outside the building or to cover the crowding area to prevent sharp contrasts in lighting that cause cattle to balk at important points in the handling facility.

Cattle like to maintain visual contact with each other, so in most situations, the single-file alley leading up to the squeeze chute should be at least 20 ft. long (30 to 50 ft. for larger facilities) to allow each animal to see others ahead of it. Don’t force an animal into a single-file alley unless there is plenty of room. If cattle see a dead-end, they will most likely balk, therefore, blocking gates in a single-file alley need to be “see through” so cattle can see the animals ahead.

To protect all the people handling cattle, the corrals, working facilities and chutes must be in good repair and must match the operation and cattle. Gate latches and latches on the squeeze chute (head-catch and squeeze) must have scheduled, proper maintenance because slipped latches are very dangerous. All persons using the squeeze chute should know where the pinch points are, and the arc of movement of squeeze bars and head catch handles. Pipes slid behind cattle to serve as a back-stop are dangerous because an animal moving either forward or backward rapidly before the pipe is fully engaged can trap a person between the pipe and the side of the alley or chute. And to prevent being injured directly by an animal, do not get in the crowding area or alley. Also, the working area should be easy to clean and provide non-slip flooring in the crowd pens, alleys, chutes, and the exit from the chute.

While good working facility design, construction, and maintenance are important for safe and efficient cattle handling, the people handling the cattle probably have the greatest impact on the level of stress inflicted on the cattle and handlers and the ease that cattle move through a facility. Most cattle producers know of people who handle cattle particularly well (as well as people at the opposite extreme). We use terms like cow-sense, common-sense, or stockmanship to describe people who are able to observe cattle behavior accurately and then respond to that behavior so that cattle move exactly where the handler wants them to move. Although there may be some in-born personality traits or skills that make some people naturally better cattle handlers, good cattle-handling training that emphasizes unlearning bad habits and learning low-stress cattle handling habits can benefit anyone who routinely works with cattle.

            It is easy to recognize that handling cattle is required for many, if not most, animal health procedures. In order for health and production management interventions to provide the greatest benefit to a cattle herd, the cattle must be handled through good facilities quietly, efficiently, and with minimal stress.

Commitment to Excellence in Herd Health

Bob L. Larson, DVM, PhD
Beef Cattle Institute
Kansas State University

Beef producers have many demands on their time and attention. One of those demands is to achieve excellent health for their herd. In general, cattle can remain healthy in a wide variety of environments and when under a variety of stresses. However, young calves, cows around the time of calving, and cows and their fetuses in the early stages of pregnancy are more at-risk for experiencing health problems than cattle of other ages. In addition, individuals or herds that have to deal with more than one problem at the same time can have severe health problems.

In my opinion, the secret to excellence in herd health is to focus on time-tested aspects of animal husbandry while utilizing some aspects of more modern technology.  The term “animal husbandry” may have gone out of favor in some circles, but it describes the care and feeding of livestock based on good observation skills and a daily commitment to the health and welfare of the animals. Focusing on maintaining good forage availability, good body condition of cattle, and a clean environment that allows for protection from severe weather and predators are long-standing attributes of the best cattle producers. In the past century, additional tools have become available to help improve cattle health. These include advancements in forage management, feed evaluation, internal and external parasite control, vaccines for disease prevention and control, tests for the identification of cattle carrying contagious organisms, and genetic selection to reduce the risk of calving difficulty and other common problems. Combining these modern technologies with age-old husbandry skills allows today’s beef producer to achieve a level of health for their cattle herds that was not possible in the past.

Good cowherd nutrition is built on the foundation of good forage production and management. Abundant growing grass is a fantastic feed that usually results in excellent health of grazing cattle. Cattle can use a wide variety of plants for a healthy diet, but if drought or over-stocking reduces the amount of forage that cattle can consume, health problems are likely to follow. All forages are deficient in salt and providing salt throughout the year is necessary in all parts of the U.S. In addition, other minerals are also needed in cattle diets, but in many areas the available forages provide all or most of a herd’s other mineral needs. In areas or pastures with known mineral deficiencies, specific minerals such as phosphorus, copper, zinc, selenium, or other minerals will need to be supplied. During the winter or other times of the year when forage is dormant, protein and other nutrients may need to be supplemented to ensure that the herd is receiving an adequate diet to maintain body weight and optimum health. Research at universities and other locations over the past several decades have provided nutritionists and veterinarians with valuable information and tools to balance forage-based diets for cattle at the different stages of production such as growth, pregnancy, and lactation.

In addition to a commitment to provide adequate forage and supplements, the other aspect of animal husbandry excellence that has been passed down through the ages is to provide an environment that is clean and gives protection from weather and other stresses. Because cattle are housed outdoors, the natural occurrences of dust and mud are not completely avoidable; but throughout time, the best animal caretakers provided excellent environments for their cattle given the rainfall, snow storms, and other weather events that are common for their area. The best mud-control strategies for cattle on pasture is to make sure that cattle spread out and do not congregate in an area where the combination of rainwater or snow-melt and the hoof action of cattle result in deep mud. The amount of space needed to minimize the risk of problems due to mud will depend on the expected rainfall patterns for an area. Making sure that shelter as well as water, salt, and feed sources are spread to various parts of a pasture will keep cattle from spending too much time as a group in a small area. Mud control strategies for cattle that are housed in drylots include good design and construction of pens to allow water drainage, and frequent scraping to maintain a good pen surface. In areas of the country that can experience severe winter storms, cattle need to be able to find natural or man-made wind-breaks and to have access to areas with good draining that are free of standing water and mud.

One of the greatest advancements for cattle and cattle producers that modern technology has provided has been in the area of parasite control. Throughout history, worms (or internal parasites) and flies and other insects have caused tremendous discomfort, disease risk, and production loss for cattle. Appropriate use of chemicals to interfere with the life-cycles of parasites allows cattle producers to remove much of the negative effect of these pests. Because parasites are very numerous and have the ability to adapt to changing environments and risks, they continue to cause health and production problems. Internal parasites cause more severe problems in young cattle and in cattle that live in warmer parts of the country that have larger parasite populations because they lack the benefit of killing winter temperatures. By working closely with a veterinarian, cattle producers can implement strategies to control parasites for the short-term while making sure that they don’t contribute to the development of pests that resist chemical control.

The knowledge and technologies that make accurate EPDs possible provide a tremendous benefit to cattle producers by giving them tools to reduce the risk of calving difficulty. The period of time with the greatest risk for both calves and their dams is at and shortly after calving. Difficult births cause direct problems for both the dam and the calf and even if a calf survives a difficult birth, the stress of that event as well as reduced colostrum intake combine to increase his risk of death due to scours, navel ill, or pneumonia during the first few months of life. Through good bull selection and heifer selection and development, modern beef producers have tools to reduce the risk of difficult calving that earlier generations would envy.

And finally, an over-arching strategy to achieve excellence in herd health includes using vaccines to reduce the risk and severity of some important cattle diseases, and antibiotics and other modern drugs to treat illnesses and injuries that affect cattle. These advancements in disease treatment and prevention options are valuable, but they must be used correctly and as enhancements and not replacements for good cattle husbandry.  Following Beef Quality Assurance (BQA) guidelines to ensure that all products are administered using the proper injection sites, injection routes (under the skin, in the muscle, into the vein, etc.), dosages, and withdrawal times is a critical step when beef producer commit to excellence in herd health.

Young Bull Health Considerations

Seedstock producers, bull buyers, and veterinarians all have considerable interest in the breeding ability of yearling bulls and the ability of a breeding soundness examination to accurately predict that ability. It is expected that there will be a lot of variability among young bulls, but in general by about 10 to 11 months of age, bulls will reach puberty.  At puberty, sperm cells can be detected in a semen sample, but production is limited and many sperm cells will have one or more defects and the bull would not pass a breeding soundness examination. As bulls age past puberty, sperm production steadily increases and the percentage of abnormal sperm cells in a semen sample will decrease until the age of 16 months when bulls should be sexually mature. Daily sperm production will increase until a bull is about 3 to 4 years of age when testicular weight peaks.

Breeding soundness examinations consist of a complete physical, scrotal measurement as an indication of testicular size, and a semen evaluation. The need for breeding soundness examination of bulls is based on the fact that many prospective breeding bulls are infertile, subfertile, or unable to successfully mate. The physical examination includes observing the bull as he moves – looking for inadequacies in movement, leg conformation, and general body condition. The physical examination continues once the bull is confined in a squeeze chute – noting any abnormal conformation. The lungs and heart are evaluated and a rectal exam is performed to determine the health of internal reproductive organs. The penis should be extended and examined for indications of injury, warts, persistent frenulum, or disease. The testes and epididymis are palpated for evidence of degeneration or inflammation.

An easily obtained and important measurement for evaluating young bulls is the scrotal circumference. Although bulls will reach puberty at wide range of ages and weights, bulls of all breeds tend to reach puberty when the scrotal circumference is pretty close to 28 cm. Remember that a bull that has just recently reached puberty will produce very few fertile sperm cells and he would not be expected to successfully breed more than a few heifers or cows. Typically, young bulls between 10 and 16 months are described as “yearlings” but testicular size and scrotal circumference increases rapidly during this period so it would not be appropriate to directly compare young bulls that differ in age even by as little as a month.

Once the physical examination is complete and the scrotal circumference has been determined with a tape measure, a semen sample is collected either with the aid of an electroejaculator, massage of the prostate, or use of an artificial vagina and a mount animal. The semen sample is evaluated for sperm motility and for the presence of excessive numbers of abnormal sperm. Interpreting semen samples of young bulls less than 13 months of age can be difficult; and while bulls 10 to 13 months of age can be evaluated for scrotal circumference and physical soundness, some veterinarians and seedstock producers choose to delay evaluating sperm quality until a bull is 13 or 14 months of age. Bulls less than 13 months of age that have an excessive percentage of abnormal sperm may very well be too close to puberty and if allowed to mature a little longer will have more than 70% normal sperm cells and be considered a satisfactory breeder. However, if a 14 month old or older “yearling” bull fails a breeding soundness examination because of excessive numbers of abnormal sperm cells, it is fairly likely to fail a breeding soundness examination if tested again at 16 months of age.

Although there is still much to learn about the steps that should be taken to ensure that the greatest number of bull calves can become successful herd bulls, a number of studies have indicated that nutrition in the first few months of life prior to weaning has a tremendous impact on the age at puberty, mature testicular size (and scrotal circumference), and mature sperm production. Energy or protein restrictions in young suckling bulls (usually due to limited forage availability or poor dam milk production) can permanently reduce fertility. Another concern is that if young bulls suffer from any disease prior to weaning, the disruption of growth and health during critical periods of sexual maturation could have permanent negative effects on fertility. These concerns focus our attention on a herd health plan that includes good sanitation, nutrition, parasite control, biosecurity, and vaccinations to minimize the risk of disease.

In contrast to the importance of diets that are adequate for energy and protein very early in life, providing high levels of energy after weaning has not consistently shown any benefit to age a puberty or later fertility. In fact, if high energy diets post-weaning result in fat accumulation in the neck of the scrotum, fertility can be reduced, and bulls that become over-conditioned post-weaning are at increased risk of joint problems in their legs and possibly other problems.

A plan to ensure the health and adequate growth of bull calves prior to weaning and on through to yearling age is essential for optimum bull fertility. Because of the rapid changes that take place after a young bull reaches puberty, evaluating semen quality can be difficult and unproductive before a bull has had the opportunity to mature to the point where he can express his true fertility at about 13 to 14 months of age.

Navel Infection

As we prepare for spring calving, an important health concern in young calves is navel ill which can lead to joint ill. Navel ill occurs shortly after birth when bacteria from the environment or skin are able to enter the calf through the navel and cause an infection or abscess in the umbilical (navel) area. If the infection gets into the blood stream and spreads throughout the body, joints in the legs are likely to become infected and the problem becomes “join ill”.  

The bacteria that cause navel ill or joint ill are very common but are only likely to cause problems if the calf is born in a dirty environment or does not get enough colostrum. So, prevention of this problem focuses on avoiding calving in drylots (or mud lots) so that exposure is minimized, and by minimizing the risk of calving difficulty (particularly in heifers).  

In order for a calf to consume adequate amounts of colostrum, it must be able to stand, walk, find the dam’s teats, and suckle within six hours of birth and then suckle several times in the next 12 hours. In addition, the dam must stand, have a good maternal bond with the calf, and have teats that can be grasped by the calf. Calves born unassisted (i.e., without need of human intervention) stand more quickly, are more likely to bond with their dam, and have greater consumption of colostrum, compared to calves that required assistance during birth. Furthermore, calves requiring minimal assistance are at a substantial advantage compared to calves requiring more assistance during delivery. Proper heifer development and nutrition, use of calving-ease EPD bulls on heifers, and appropriate cow nutrition are good strategies to decrease the risk of calving difficulty. 

Despite the importance of adequate antibody passage, colostral intake is not the only factor that determines whether calves develop navel or joint ill. The other important factor that determines the number of sick calves and the severity of disease is the amount of exposure to disease-causing germs. The ideal location for calving is on well-drained pastures. If heifers or cows need to be moved to a drylot location for calving, extra attention should be given to improve sanitation and to treat the navel of newborn calves with iodine.  

To ensure that calves are born in a sanitary environment, pregnant cows and heifers should be moved from wintering pastures to a clean calving pasture just before start of the calving season. The calving area should be free of mud and should be protected from the wind. A large pasture with good drainage and a natural windbreak is probably all that is necessary for many mature herds. An additional factor that adds to the risk of infectious disease in young calves during severe weather is that cattle will often gather into a small area because of excessive snow or surface water or because of the practice of repeatedly placing feed and bedding in the same location. Producers may also intentionally move cattle into a small area in an attempt to provide them shelter from severe weather. These small areas rapidly become crowded and muddy, which leads to an increased possibility of navel or joint ill in the calves. 

Dipping the navel of newborn calves in iodine can be helpful if the calf is born in a dry-lot or other unsanitary area or if the calving was assisted. If calves are born on well-drained pastures and are experiencing very little calving difficulty, dipping navels is less important.  

Signs of navel or joint ill can occur as early as two days of age. If only the navel is involved, it will usually appear enlarged and wet. If the infection has moved into the blood stream, the calf may appear depressed, have lameness or swollen joints, have cloudy eyes, have a poor appetite or diarrhea, or have a fever. Early in the disease, the navel may not be enlarged. Other diseases and problem can have the same signs as navel ill, so often a veterinarian must examine the calf or calves involved to make a diagnosis. Treatment of calves with joint ill that also have signs of nervous system (brain or spinal cord) disease is not likely to be successful and euthanasia of the calf should be considered. Calves with more than one chronically infected joint as well as an infected navel also have a slight chance for recovery.  

If the infection is limited to the navel area and has not invaded any joints, treatment with antibiotics for several days and possibly surgical removal of the infected navel area have a good chance of being successful. If joints are involved and treatment is attempted, it must be aggressive by using approved broad-spectrum antibiotics for several days. Oral or IV fluids are given to treat and prevent dehydration. Other care may include heat lamps, adequate nutrition, clean, dry bedding areas, and possibly your veterinarian my flush the affected joints.  

When treatment is aggressive, the cost can be quite high. However, if the calf is severely affected, less-aggressive treatment is not likely to be successful. Obviously, prevention by decreasing calving difficulty and improving sanitation is preferable to death, production loss, or high treatment cost for affected calves.  

Vitamin A

Although I usually emphasize energy and protein intake when planning winter cow nutrition, ensuring adequate vitamin A intake is also important. Vitamin A is the vitamin most likely to be deficient in cattle diets and is the only vitamin with a well-defined requirement. It is important for vision, bone formation, growth, reproduction, and skin and other tissue health.

Cattle convert yellow and green pigments (carotene) in plants into vitamin A. Carotene is in all green plants and is plentiful in fresh, leafy forage but not found in high concentrations in many concentrate feeds. Cattle can store excess vitamin A in the liver for 2 to 4 months. This storage can serve as source when feeds are deficient. Because of this ability, cattle on green pasture can often store sufficient reserves to help meet their needs during the winter-feeding period when rations may be deficient.

            Large losses of carotene take place in the curing and storage of roughages. Hays that are cut in the bloom stage or earlier and cured without exposure to rain or excessive sun retain most of their original carotene content, while hay cut in the seed stage and exposed to rain or to extended periods of sunshine lose most of the carotene content. Hay rapidly cured with a drier only has a slight loss of carotene. The degree of greenness in roughage is a pretty good indicator of its carotene content. Both carotene and vitamin A are destroyed by oxidation, which can occur during feed storage. The stability of supplemental vitamin A has been increased by modern milling practices such as covering minute droplets of vitamin A with gelatin or wax or by adding an antioxidant to the feed.

            Vitamin A deficiency is most likely to occur when cattle are consuming a high concentrate diet, grazing dormant pasture or eating hay grown during drought conditions, eating feeds that have been stored for long periods of time, or when consuming a protein-deficient diet that is also low in vitamin A. Deficiencies can be corrected by increasing carotene intake by adding fresh, leafy, high-quality forages to the diet, by supplying vitamin A supplements in the feed, or by injection of vitamin A preparations.

The classic sign of vitamin A deficiency in cattle is night blindness (difficulty seeing in dim light) with total and permanent blindness possible in younger animals, and blindness in calves born to deficient dams. Excessive tearing (watery eyes) in cattle also occurs. Vitamin A deficiency can also be identified in animals with rough, dry, and faded hair coats, overgrown hooves that are dry and brittle, and hooves with multiple, vertical cracks. Vitamin A deficiency has also been identified as a cause of infertility in both females (delayed or lack of ovulation, silent heat, and early fetal loss) and bulls (abnormal semen). In addition, because vitamin A is important for the normal function of the tissues lining the respiratory tract, digestive tract, and the urinary tract; pneumonia, diarrhea, and urinary tract stones are also seen in cattle with vitamin A deficiency.

Although clearly identifiable cases of vitamin A deficiency are not particularly common, herds that do not reach their potential reproductive performance, growth rate, and health because of limited vitamin A in the diet are seen. Because the vitamin A activity in typical beef cattle rations is very unpredictable, the total requirement is usually added to the diet as a stabilized vitamin A product. Vitamin A palmitate and vitamin A acetate added to the feed provide relatively inexpensive supplementary sources. Vitamin A can also be given as an injection, with the vitamin being stored in the liver for a number of weeks. Vitamin A requirements for cattle range from 2,000 – 8,000 IU (international units) per 100 pounds of body weight. Growing cattle, lactating cows, and bulls require higher levels of vitamin A than mature dry cows. Vitamin A is very safe to use in cattle feed because toxicity is extremely rare.

            As we move into the winter months when most cow herds will be receiving rations composed of dormant or stored forages, vitamin A supplementation is one of the fist items to consider when planning an appropriate diet.

Monitoring Winter Body Condition

Cows in moderate body condition (BCS 5 to 6) usually require an average of about 55 to 65 days to resume fertile cycles after calving – meaning that mature cows that calve during the first 35 days of the calving season in moderate body condition should be cycling during the first 21 days of the next breeding season starts. In contrast, cows that calve with a BCS of less than 5 require more days to resume fertile cycles, and have very little chance of having fertile cycles by the start of the next breeding season – possibly not until late in the next breeding season.

Good body condition at calving is even more important for the reproductive performance of young cows that are nursing their first calves compared to mature cows because first-lactation cows often require 80 to 100 days to resume fertile cycles after calving. First-calf cows must have a BCS of 5 or greater (preferably 6) to have acceptable pregnancy rates for their second breeding season. In order to reach or maintain a BCS of 6 for first-lactation cows, they should be separated from the mature cowherd and fed to gain the needed weight.

During the winter months, most cattle in the U.S. are consuming dormant or baled forage. In most situations, the forage is poor to moderate in quality. When cattle graze marginal to low quality forages, supplemental protein or energy is often required to enhance either forage intake or animal performance. Poor quality forages (grazed or hay) have two negative effects on cow diets – the first effect is lower intake. While a 1250 pound cow will consume about 31 pounds (as fed) of moderate to good quality forage, she will only consume about 24 pounds of poor quality forage. The second negative effect is that the amount of energy per pound of intake is reduced compared to higher quality forage.

Because of year-to-year variation in forage quality and weather stress, cow body weight and condition can have important year-to-year variation even when fed what appears to be the same diet. Slightly lower forage quality and increased weather stress can result in cows losing more weight than expected. If cows lose condition over the winter so that that they enter the spring-calving season with a poor body condition, calf health and cow reproductive efficiency will be negatively affected.

In general, mature cows in good body condition that are not nursing a calf and that only need to maintain weight can over-winter on forage alone if forage quality is at least moderate and weather stress is low. If cows in good body condition are forced to consume lower-quality forage or if winter weather is harsh, supplemental high quality forage or concentrate will be required to maintain body weight. If cows are thin and need to gain body weight prior to calving, moderate quality forage will not supply the needed nutrients, and supplemental concentrate or high quality forage must be fed. If only poor quality forage is available, even greater levels of supplement must be fed to add body condition to thin cows prior to calving.

Young cows carrying their first pregnancy require energy and protein for their own growth as well as fetal growth, which makes their nutrient requirements higher than those of adult cows. Most dormant or baled forages do not provide all the calories needed for first-pregnancy cows over the winter, especially if the cattle face any weather stress. Ranchers should plan on providing young cows with supplemental high-quality forage or concentrate for at least part of the winter. The amount of supplement required depends on the quality of the base forage (grazed or baled).

In order to determine the amount of supplement required for the available forage, you need to be able to estimate how much energy reserve the cows’ are storing as body fat. Body condition scores (BCS) are used to describe the relative fatness or body fat reserves of a beef cow. The most commonly used system uses a range of 1 to 9, with a score of 1 representing a very thin cow and 9 representing an extremely fat animal.

Body condition scores are an accurate measure of body fat and are convenient in that cattle do not need to be weighed, merely observed and palpated at a time when other procedures are performed. Depending on mature cow size, there is approximately 80 to over 100 lbs. difference in body weight per BCS. When evaluating body condition, it is important to handle the cattle, so that one is not mistakenly evaluating hair coat, gut fill, or stage of pregnancy. The areas to palpate when determining BCS are: ribs, back, backbone, and tailhead. The entire herd, or a subset of each age group, should be evaluated for BCS during the winter to allow adjustments in winter supplementation to occur before cows lose excessive body weight.

It is very difficult for cows to gain body weight on dormant forage once they have calved and started lactating – even if heavily fed. Therefore, cows should reach their desired breeding body condition by the time they calve. In order to have enough days for thin cows to gain weight, herds should be evaluated 3 to 4 months prior to calving. If evaluated at this time, the weight gain for a BCS 3 cow to reach breeding condition (BCS 5) will be approximately 1.5 to 2.0 pounds per day (which is very possible with good forage and supplementation). In contrast, if cows only have 2 months to gain 2 body condition scores, they will need to gain over 3 pounds daily – a much more challenging task.

Anaplasmosis

By Bob Larson

Anaplasmosis is a serious disease that affects cattle in an increasing larger area of the country. A tiny organism called Anaplasma marginale attaches to red blood cells which leads to destruction of those cells and a decrease in the ability of affected cattle to carry oxygen in their blood. If more red blood cells are destroyed than the animal can replace with new cells – the blood becomes watery, the animal becomes anemic, and other signs of infection can occur, including: fever, depression, dehydration, rapid or difficult breathing, and yellow discoloration of the mucus membranes of the gums, around the eyes, and the vulva. Sometimes affected animals become excited and aggressive when not enough oxygen reaches the brain. Young animals are often able to recover because they can make new red blood cells very quickly, but older animals do not produce new cells very fast and they can quickly become very anemic and have very low oxygen levels in the blood leading to severe illness or death.

            Anaplasmosis is primarily carried from cattle to cattle by ticks, but the movement of blood from infected cattle to susceptible cattle can also be accomplished by biting flies such as horseflies, or by human activities such as via blood-contaminated needles, dehorning instruments, tattoo pliers, or palpation sleeves. The disease has historically been a problem in the southern parts of the United States but has now spread north so that cattlemen in many important beef-producing areas need to be aware of the problem. In herds that become exposed to the organism, cattle of any age can become infected, but the severity of illness is usually mild in young cattle and increases with age. In cattle that become infected when they are 3 years of age or older, 30% to 50% of animals showing signs of the disease are likely to die. If infected cattle are able to survive they are not likely to have severe problems due to the disease in the future, but they remain as carriers for the rest of their life. In some cases these carrier infections can be eliminated using antibiotic treatment.

            The first sign of anaplasmosis in a herd may be the sudden death of adult cattle. If anaplasmosis is identified as a cause of death and disease in a herd, cattle that are obviously sick should be kept as quite as possible and treated with an appropriate injectable antibiotic to kill the organism. In addition, tetracycline can be fed in the mineral mix or supplement to provide additional protection to the herd as directed by a veterinarian through a VFD document.

            For carrier cattle that don’t appear sick but that are infected with the anaplasma organism, your veterinarian can plan a treatment protocol using approved antibiotics administered over several days to clear the organism. However, treatment with antibiotics is not effective for all cattle and those animals that are cleared of the organism become susceptible to re-infection.

            The best plan to minimize disease lose due to anaplasmosis depends greatly on a farm’s or ranch’s geographic location and the number of cattle in the area that are infected. In parts of the country where anaplasmosis infection is rare, a strategy to find and treat and/or remove any carrier-animals is recommended. In contrast, in areas of the country where many cattle are infected, an attempt to remove all carriers from a herd will result in a herd that is susceptible to re-infection and the herd may have greater losses than if other strategies had been used to minimize the disease’s effects.

            If infected cattle are found in a herd in a part of the country where anaplasmosis is rare, one strategy to minimize disease loss is to test the herd for anaplasmosis infection and to treat any test-positive animals with an appropriate antibiotic as directed by your veterinarian. This treatment should be at a time of year when the local tick and fly population is the lowest. Because the treatment does not clear infection from every animal, the animals should be tested again about six months after the treatment and if an animal tests positive at this time, it should be considered a treatment-failure and removed from the herd, either by slaughter or by being sold to a herd in an area where anaplasmosis is common.

            In contrast, in herds located where anaplasmosis is common, rather than trying to avoid infection, some producers may want to allow infection to occur while the cattle are young in order to minimize obvious sickness and death loss. In some countries young animals are purposefully exposed to the organism allowing them to build immunity at a time in their life when the disease is mild. Although they will be infected for life, they are not likely to suffer severe illness. In some states in the U.S., your veterinarian may be able to obtain an experimental anaplasmosis vaccine that does not prevent infection, but is reported to reduce the risk of clinical signs and death. Producers may also elect to feed tetracycline under that direction of a veterinarian when the disease is most prevalent to control active infection and to use insecticides to control tick and fly populations.

            Because the best anaplasmosis control strategy for a particular farm or ranch depends on how likely that herd is to come into to contact with the organism, an important component of a control strategy is a plan to deal with replacement animals. If your herd is free of anaplasmosis and the risk of exposure is low, any replacement animal should be tested before being brought into contact with the herd. A test-positive animal should either be culled or isolated and treated and then re-tested six months after treatment. In contrast, if your herd is infected with anaplasmosis and the organism is common in your area, a test-positive replacement animal is desired, and the greatest health risk is in replacement animals that are not infected with the organism but that will be placed in direct contact with carrier animals. In this situation, one option is vaccination (if available) with close monitoring for clinical signs of the disease and quick treatment if disease is detected.

            Anaplasmosis control requires a good working relationship with your veterinarian to determine your level of risk and best control strategies. The best control strategy for your herd may be very different from that of your neighbors or cattlemen in other parts of the country.

Nutritional Aspects of Cattle Health

Bob L. Larson, DVM, PhD 
Beef Cattle Institute
Kansas State University

Meeting the nutritional needs of cattle is the foundation of a healthy herd. Nutritional needs differ between bulls, dry cows, lactating cows, growing replacement heifers, and post-weaning calves; and the nutrient composition of forages change throughout the year. Because of the interaction between changing animal needs and changing forage conditions, herd managers must be informed and prepared to provide appropriate supplements when needed. In almost all situations when cattle have the opportunity to graze green growing forages that are high-quality and readily digestible, the only supplement needed is salt (and based on local soil and plant characteristics, possibly other minerals). However, even green growing grass has the potential to cause health problems if the concentration of the mineral magnesium is low in the lush leaves at the same time that cows grazing the forage have high magnesium requirements due to being in early lactation or late pregnancy.  

While green growing forage is an excellent feed source for cattle, because of weather factors and growth characteristics of grass, for many weeks of the year cattle only have access to mature or dormant forage that has reduced quality and digestibility. Standing dormant forage and moderate-quality hay can meet most, if not all, of the energy and protein needs of cattle that have relatively low nutritional demands, such as mature cows that are not lactating and bulls that are not active. But if cattle are growing or lactating, dormant forage or hay may be deficient in energy and/or protein and these nutrients must be supplemented to avoid inadequate growth or even weight loss. The maturity and quality of forage when it is cut for hay as well as the conditions in which the hay dries before baling have tremendous impact on the nutrients present. Waiting to cut hay until the forage is very mature may increase the tonnage available, but the quality may be so low that either the cattle will not be provided needed nutrients or the needed supplementation drive up the total diet cost. Because growing replacement heifers, growing bulls, and cows in late stages of pregnancy or early lactation have high nutrient needs, these classes of cattle require higher quality forages or more supplementation of poor-quality forage than adult, non-lactating cattle.     

Because forages and readily available energy and protein supplements vary greatly across North America, knowledge of the local forages and feeds is essential when planning the most cost-efficient diets for cow herds. The types of predominant forage plants and the growth patterns of the different plants in diverse areas of the country greatly impact the quality of the diet for grazing cattle. Many forages and feeds have specific characteristics that affect not only the diet quality but also potential negative effects; and knowledge and experience is needed to avoid health and production problems. Use of some supplemental feeds has to be limited due to adverse effects when fed at higher levels. For example, the high starch content of corn and other grains limits their use in forage-based diets, the potentially high levels of sulfur in corn gluten feed, distillers grain, and some other by-product feeds requires that they be used in moderation, and gossypol in cottonseed meal can cause reduced fertility in bulls which requires that this feed be fed for limited time or in limited amounts in the weeks ahead of the breeding season.  

Cattle that are not receiving adequate amounts of water, energy, protein, salt and required vitamins and minerals can exhibit a wide range of problems that includes poor growth, weight loss, failure to become pregnant, hair and skin lesions, bone and joint problems, and susceptibility to sicknesses such as pneumonia, scours, and nervous system disease. Unless underlying nutritional problems are identified and corrected, use of vaccines, antibiotics, and other interventions will not improve heard health. In many situations, outright disease is not detected, but nutrient deficiencies are negatively impacting body weight and fertility of the herd. 

Fortunately, cattle will thrive on many different types of forages and feeds. The rumen has the ability to convert moderate- and even low-quality feeds into needed nutrients. Because cattle can eat a wide variety of feeds, locally available products that could not be easily shipped to other parts of the country or could not be used in other animal diets can serve as excellent cattle feeds. Knowledge of the nutrient needs of different classes of cattle as well as experience with local forages and feeds will allow cattle producers and their advisors to develop cost-effective diets that meet the needs of cattle to maintain good health and productivity. 

Health Risk when Purchasing Cattle

Bob L. Larson, DVM, PhD
Beef Cattle Institute
Kansas State University

One issue in the buying and selling of cattle that is often not considered until a problem arises is the health aspects of the transaction. While every business deal involves some risk, including health risk, the level of risk is not the same for every transaction and producers and their veterinarians have options to lessen the likelihood and/or extent of negative outcomes.

In general, the less health information that is available for a sale animal, the greater risk the purchaser is taking. In many situations, the seller does not does not possess specific information about the health of the cattle they are selling or the potential negative outcomes that may occur when the purchased cattle are introduced into the buyer’s herd. Because a number of negative health outcomes can follow the introduction of new cattle into a herd, the buyer needs to beware of taking greater risks than should be reasonably expected.

When purchasing cattle to introduce into an existing herd, some potential health risks include: injury during transport, the stress of transport and a new environment causing a purchased animal to break with disease leading to illness of the purchased animal or transfer of germs or parasites to the herd, the purchase of cattle that have not been exposed to the germs commonly found in the home herd leading to illness of the purchased animals, and purchasing an animal that is a persistent carrier for an infectious disease and exposing the home herd to an unfamiliar germ.

The risk of injury can be decreased though careful handling and good loading, unloading, and transport equipment. Good design and maintenance as well as appropriate flooring and bedding in transport trailers along with a transportation plan that includes considerations of length of travel, weather exposure during travel, and skill of the driver to avoid excessive fatigue on the part of the cattle being moved are all considerations to reduce the risk of injury of purchased cattle.

Cattle that are stressed are more likely to become ill and to shed germs and parasites that can be spread to other cattle. Even when healthy cattle are transported to a clean environment in safe transport trailers, some level of stress can be expected. This potential period of greater susceptibility to disease and greater risk of exposing other cattle to disease-causing germs is the reason that veterinarians recommend that cattle being added to a herd are separated (quarantined) from the current herd for a period of at least 30 days so that the new cattle can become completely acclimated and can have recovered from the stress of being transported to a new environment.

Even though the purchaser of new cattle are often concerned about any germs or parasites that the new cattle may be bringing into their current herd, an equally important risk is that newly purchased cattle may be exposed to unfamiliar germs present in the home herd – causing the new cattle to become sick. This risk can be addressed by using a period of time after the original 30 days of complete separation from the current herd to allow limited contact of the new additions with a few cattle from the original herd. Older cows or animals that are being culled are often used for this purpose.

And finally, the risk that many veterinarians and producers consider first when protecting a herd from the risk of introducing new cattle is purchasing an apparently healthy animal that is a persistently infected carrier of a disease that is not currently a problem in the herd. There are a number of important diseases that can enter a herd by the purchase of a carrier animal. In my opinion, the diseases that fall in this category that deserve the greatest attention in many parts of the U.S. are trichomoniasis (trich) and bovine viral diarrhea (BVD). Other diseases that have persistent carriers and that may be of particular concern for some herds include: anaplasmosis, Johne’s, and bovine leukosis virus (BLV).

Because of the amount of loss that can occur and our current disease-control abilities, no herd should tolerate the import of cattle infected with trich or BVD. However, for some of the other diseases that have persistently infected carriers, it is not always wise to insist in imports being free of the disease-causing germs. For example in some parts of the country where anaplasmosis is extremely common, it may be better to purchase cattle that have been exposed to the organism previously and are themselves carriers. In contrast, if you live in an area with very low anaplasmosis risk, you need to protect the home herd by purchasing cattle that are not carriers. For diseases such as Johne’s and BLV, many herds already have carrier animals and insisting that purchased replacements be negative won’t make much impact on the current herd’s health status.

In summary, my advice is to have plans to keep any cattle potentially infected with trich or BVD out of a breeding herd and to know the status of your herd for any other infectious agents you may want to exclude. Work closely with your veterinarian to develop the best for your specific herd to manage the risks of brining in new cattle to your herd. In many situations, it is helpful for your veterinarian to talk to the supplier’s veterinarian so that the health status of your herd and the source herd can be compared. You should have a quarantine time when you can watch herd additions closely for at least 30 days. If any of the purchased cattle show signs of illness during that 30-day period – keep them quarantined longer so that a full 30 days passes after the last episode of illness until the new cattle are allow to have contact with your herd. At the end of the quarantine period, consider exposing the herd additions to older (possibly culls) cattle so that purchased cattle are exposed to the home-herd’s germs and parasites while you can still watch them closely.

Purchasing herd additions that meet the genetic and marketing goals for your ranch is an important part of ranch management. Managing herd additions to limit the health risks involved is an often overlooked consideration in the transaction.

Coccidiosis

Bob L. Larson, DVM, PhD
Beef Cattle Institute
Kansas State University

Coccidiosis is an important disease of cattle caused by a small parasite that invades the cells of the intestinal tract and if enough intestinal cells are damaged, diarrhea or bloody-diarrhea can result. You may have heard of other species that also can suffer from coccidiosis, including poultry and swine. However, although most animal species can be infected with coccidia organisms, the specific types that cause disease in other species will not cause problems for cattle – cattle disease is caused by cattle coccidia. Almost all cattle are infected with at least a few coccida organisms, but problems only occur if the parasite can multiply rapidly – usually when cattle are stressed. The stress of weaning, trucking, weather insults such as winter storms or mud, over-crowding, or poor nutrition can all allow individuals or groups of cattle to suffer from coccidiosis.

Recently weaned cattle, particularly if they are exposed to inclement weather or mud and are shipped to a new location are considered to be at high risk for coccidiosis. Young suckling calves can be affected, particularly in situations with poor sanitation, nutritional stress, and other causes of diarrhea. Adult cattle that remain in the herd are usually immune to the local coccidia, but thin cows can be at risk. In addition, bringing in new cattle can cause an outbreak of coccidiosis in the new animals when they are exposed to the local coccidia – or the new animals may bring in a new species of coccidia and cause an outbreak in the original herd.

The most common signs of coccidiosis are watery diarrhea, diarrhea with blood, straining to defecate, a rough hair coat, and poor weight gain. In addition, some affected cattle in a group can show signs of nervous system problems such as tremors, eye twitching, and convulsions. Many cattle with coccidiosis appear healthy but they have decreased weight gain and feed efficiency. Mild cases that involve a few days of watery feces without noticeable blood where the cattle do not become obviously depressed or off-feed are also common. Severe cases with a week or more of bloody diarrhea can lead to a fever, becoming off-feed, and being depressed and dehydrated. If the infection is mild, death is very rare, but in more severe cases, death is fairly common due to coccidiosis itself or the coccidiosis can increase the risk for other severe diseases such as pneumonia. Cattle with nervous system symptoms have a very high risk of death.

Your veterinarian is most likely to diagnose coccidiosis after examining cattle with bloody diarrhea and ruling out other problems. The organism can often be detected in high numbers in fecal samples, but this test is not always accurate because intestinal damage can occur before large numbers of coccidia are found in the feces. In addition, some cattle may have high numbers of coccidia in their feces, but be nearly recovered from the disease and are in much better shape than cattle with few or no organisms earlier in the disease process.

A number of treatments are available for cattle suffering from coccidiosis, and affected cattle should be separated from the group so they can be kept comfortable while being individually treated with fluids to correct dehydration and with drugs that will kill the organism. Whenever one or more cattle in a group have obvious signs of coccidiosis, you can assume that the rest of the group has been exposed and is likely to be suffering less obvious losses.

To prevent coccidiosis, good animal husbandry practices to improve sanitation and reduce stress are important. The organisms survive very well in the environment and it is probably impossible to completely remove them from areas where cattle live. Young animals should be kept in as mud-free an environment as the weather will allow; and feed and water should be kept off the ground as much as possible to minimize fecal contamination. To reduce stress, castration and dehorning should be done at a young age several weeks ahead of weaning, and low-stress weaning strategies should be implemented wherever possible. In addition to management strategies, a number of treatments such as ionophores, decoquinate, or amprolium can be delivered by feed or water to groups of cattle to minimize the risk of severe disease. A month or more of daily intake of these preventative treatments is necessary to break the life-cycle of the organism.

As with many diseases, good sanitation and animal husbandry are important to prevent and control coccidiosis. In addition, your veterinarian can recommend products to treat affected cattle and preventatives that can be used during periods of highest risk for the disease.

Liver Flukes

Bob L. Larson, DVM, PhD
Beef Cattle Institute
Kansas State University

Liver flukes are a large flat worms that can invade the liver of cattle. The United States Department of Agriculture (USDA) reports that about 5% of slaughtered cattle are infected and their livers are condemned. Liver flukes cause economic loss through liver condemnation at slaughter as well as decreased growth and reproductive efficiency. In addition, Black disease and redwater disease are caused by clostridial bacteria that live in soil (same family as the organism causing blackleg) and if they get a “foothold” in the liver due to damage caused by flukes, these diseases can be fatal.

Because these parasites requires a specific type of water-living snail for some stages of the lifecycle, cattle in many parts of the country are not at risk; but in areas where certain snails are commonly found, a high percentage of adult cows can be infected. Cattle can only be infested by eating snails that have been infected by fluke larva. The most common fluke infesting cattle is Fasciola hepatica. The other common liver fluke is the giant deer fluke or Fascioloides magna.

Cattle most likely to be affected with F. hepatica are those in certain parts of the country that are grazing in low-lying swampy areas, flood irrigation areas, or anywhere that surface water or small, slowly moving streams favor large populations of snails. The snail that serves as the intermediate host of Fasciola hepatica is found in the Gulf Coast states and some western states. The giant deer fluke is a problem in Gulf Coast states, the Great Lakes region and the Pacific Northwest where it naturally infests deer, elk, and moose. Cattle can also become infected with the giant deer fluke and experience liver damage, but this species of fluke cannot fully mature and lay eggs when infecting cattle. In the Gulf Coast states, most fluke transmission occurs between the months of February and June. Transmission stops with the death of fluke eggs, snails, and immature flukes in the first sustained drought of the summer. In the Pacific Northwest, cold winter conditions inhibit snail and fluke reproduction.

Young flukes cause extensive liver damage as they move through the liver, but they are difficult to kill at this stage of the lifecycle. The amount of damage to the liver is related to the number of young flukes migrating through – with some cattle showing few or no signs of problems and other cattle experiencing severe problems such as diarrhea, weight loss, and a yellowing of the membranes around the eyes and vulva in heavily infested cattle. Adult flukes cause very little damage, but are relatively easy to kill with available treatments.

Even though cattle living in many states cannot become infected with flukes, cattle already infected can be transported to any part of the country and be diagnosed far from the source of the flukes. Most cattle infested with liver flukes do not appear unhealthy, and death is very rare. Some mildly infested cattle have no reduction in performance but cattle with a higher level of infestation will have decreased weight gain, poorer body condition, and decreased milk production. The poorer body condition of cows infested with flukes may lead to decreased pregnancy rates. 

Diagnosis often occurs during a necropsy or at slaughter. F. hepatica can sometimes be diagnosed by testing a manure sample, but because fluke eggs are much larger than other cattle parasite eggs, the tests commonly used for other cattle worm eggs may not detect fluke eggs even if they are present. Another problem with relying on manure sample tests to diagnose fluke infections is that flukes less than 2 to 3 months of age are immature and unable to lay eggs. Therefore, cattle can be showing signs of diarrhea and weight loss due to migrating young flukes, but the test will be negative. Even in older infections, few flukes reach adulthood and they pass a small number of eggs – therefore, an animal with a heavy fluke population could have a negative test. Because Fascioloides magna (the giant deer fluke) does not complete its life cycle in cattle, no eggs are produced or passed in the manure, so the only way to diagnose infections with this species is at slaughter or necropsy.

Most dewormers available for treatment of cattle parasites do not affect flukes. Your veterinarian can help you identify one of the available treatments that can be used in fluke infections, but these treatments only are effective against adult F. hepatica flukes (greater than 11 weeks of age) and are almost totally ineffective against Fascioloides magna (giant deer flukes). Timing of fluke treatment is very dependent on your location and grazing pattern, therefore if you live in an area with a risk of liver fluke infection, you should work with your veterinarian to devise an appropriate control plan. Removal of adult flukes will not decrease risk of liver condemnation, because the damage has already been done, but it does enhance performance in severely fluke-infested cattle and may help decrease exposure of snails living in your pastures to the fluke eggs. Prevention in areas of the U.S. that harbor the snails necessary for the liver fluke lifecycle involves draining shallow stagnant ponds, fencing cattle away from shallow bodies of water, or treatment of infested water to remove snails.

Internal Parasites

Bob L. Larson, DVM, PhD
Beef Cattle Institute
Kansas State University

Internal parasites (or worms) have historically been among the most serious health problems facing cattle. A number of types of internal parasites can affect cattle, including: roundworms, liver flukes, and coccidia. Roundworms primarily live in the gut (stomach and intestine) with one exception being lung worms. Roundworms cause problems for cattle through several pathways including damage to the lining of the digestive tract, reduced forage or feed intake, and stimulation of excessive release of chemicals by the body in an effort to destroy the parasites.

Roundworms spend part of their life cycle in the gut of cattle, while some life cycle stages must take place on pasture grasses. Adult roundworms live in cattle and produce eggs that pass out in the manure. The eggs then hatch to form immature stages that must mature on pasture. These immature stages of the parasite are eaten along with grass as cattle graze. How quickly the eggs hatch and how likely the immature forms of the worms are to survive depends on the climate (temperature and moisture), with warm wet conditions leading to rapid development and high likelihood of survival and very hot or very cold and dry conditions leading to reduced survival. In general, it takes about two to three weeks for eggs deposited in manure to develop to the stage where they can infect grazing cattle, and then they can survive for several months on infected pastures. Once inside the cattle, the parasites complete the life cycle in two to eight weeks – when they gain the ability to lay more eggs.

Calves and yearlings are the most likely classes of cattle to exhibit obvious signs of parasite infection – including weight loss, diarrhea, swelling under the jaw, dull hair coat, and unthrifty appearance. Parasite-infected adults often have weight loss or reduced weight gain, but otherwise appear healthy; although even adults can have obvious signs of parasite infection if the exposure is heavy enough or if poor nutrition or disease compromises their overall health. Heaviest exposure to internal parasites tends to occur in parts of the U.S. with warmer climate, high rainfall, and high stocking density with long grazing seasons that allows the worms to have continuous life-cycles throughout the year (i.e. southeast and south-central regions). In colder and dryer climates, the stocking density is lower and the worms have fewer life cycles in a year because there are fewer months of ideal conditions; this results in reduced parasite exposure. Regardless of the climate, the highest risk of severe parasite loads in cowherds is late in the grazing season.

The discovery of chemicals after World War II that can kill or inhibit roundworm parasites with reduced risk of toxicity to animals compared to earlier treatments have given stockmen valuable tools to decrease the health costs of these challenging adversaries. But in order for dewormers to work well and to maintain their effectiveness, parasite control must involve more than just chemical treatments.

Because young calves and yearlings are more negatively affected by internal parasites than adults, and because some pastures have very high parasite contamination while others will have very light contamination, planning a grazing strategy that places the highest risk cattle on the lowest risk pastures is an important method to minimize losses due to worms. In general, because young cattle tend to be highly susceptible to parasite infection and they quickly develop high parasite burdens, young cattle should not be grazed continually on the same pasture in parts of the country with severe worm challenges, nor should one group of young cattle immediately follow another group of young cattle on the same pasture. Pastures that have not been grazed in order to harvest hay, pastures grazed only by adult cows (without calves at-side), crop residue fields, and pastures grazed by other species such as sheep or goats would all be likely to have low parasite contamination and are ideal for young cattle.

Young cattle have very poor immune protection from internal parasites, but starting at about one year of age, cattle gain the ability to mount an effective immune response for most roundworms (and 18 months of age for the Brown Stomach Worm). If cattle can be protected from high parasite exposure until they are 12 to 18 months of age, they will develop a strong immune response without suffering serious loss. By combining grazing management with timely treatment with deworming products, cattle producers can have very effective parasite control while avoiding the over-use (or under-use) of chemical dewormers.

There are three main classes of chemical dewormers available in the U.S. with several product brands within each class. The primary purpose of chemical dewormers is not to treat cattle that have become sick or negatively affected due to high worm burdens; instead, these products should be used to limit parasite contamination of pastures so that cattle are not greatly affected in the first place. In general, cattle should be treated as they are being turned onto a pasture with a low parasite burden when the conditions are good for parasite survival. In regions of the country with heavy stocking rates and favorable environments for worms (e.g. southern U.S.), young cattle may require two or more treatments at three to six-week intervals during periods of the year that are most favorable to the parasites. None of the available products will work well if treated cattle are turned out onto heavily contaminated pasture.

More aggressive treatment and careful monitoring of conditions is vital in the southeast and south-central portions of the U.S. compared to the high plains and western states because of vastly different risks of negative effects due to internal parasites. Because the best roundworm control strategy will vary greatly from one part of the country to another and between different farms and ranches within the same area because of management options, it is important to work with your veterinarian to plan the optimum control strategy.

Lead Poisoning

Bob L. Larson, DVM, PhD
Beef Cattle Institute
Kansas State University

Many times when we think of cattle diseases we concentrate on infectious diseases caused by bacteria and viruses, or we may think of parasites such as worms, lice, and flies. But, it is important to remember that poisons can also cause rapid death and severe illness in cattle. Cattle, especially young calves, can be very curious about unusual items found in their environment, and they often explore with their tongues and mouths. Sometimes cattle will find and consume improperly disposed of farm chemicals or industrial chemicals around discard piles, electrical transformers and power line poles, or oil pump jacks, but the most common form of poisoning in cattle is due to eating lead. The most common sources of lead include batteries from electric fences and discarded vehicles, old radiators, used crankcase oil, grease from machinery, lead shotgun pellets, construction materials such as putty, lead plumbing, and old paint, and ash from fires where lead-contaminated construction materials were burned. If you ranch in an area with lead mines, the soil and water can be high in lead.

High levels of lead in the body affect red blood cells, bone marrow, and small blood vessels. It will cause abnormal signaling between nerve cells, and will severely damage the kidneys and other organs. In fact lead can have many different negative effects on the body because it can interfere with many different types of enzymes and chemicals necessary for normal body function.

Cattle are more sensitive to lead than most other species and don’t have to consume very much lead to have very sudden and severe problems. Many times, the first sign that a rancher notices is one or more dead calves within a day or two of being exposed to a source of lead. Other calves (and occasionally older cattle) in the group may appear to be blind or they may circle or press their heads against solid objects, cattle may have muscle tremors, teeth grinding, frothing at the mouth, or signs of colic. Cattle with any of these symptoms usually die within 12 to 24 hours. These signs can be very similar to other diseases such as grass tetany, polio, nervous coccidiosis, listeriosis, or rabies, so a veterinarian should be called to investigate the problem.

Because cattle are very sensitive to lead, even small amounts cause severe disease and death in at least part of the herd. Other species are not as sensitive to lead and my show mild signs of illness when exposed. Occasionally, rather than dying, older cattle or cattle exposed to very low doses of lead may show digestive tract problems such as going off feed, becoming constipated or colicky, or having diarrhea. This may be followed by signs of brain or nervous system problems such as blindness, head pressing, or staggering. Infertility of both bulls and cows has been reported following exposure to low levels of lead over a long period of time.

If calves that die due to lead poisoning are necropsied (cut open to examine the body organs), the veterinarian may find nothing that indicates the cause of death, or he/she may find some reddened intestines or lungs – which could look like a clostridial disease or pneumonia. Occasionally, the veterinarian may find evidence of unusual stomach contents, but samples of blood or kidneys are the best samples to diagnose lead poisoning.

It is generally not recommended to treat cattle with signs of lead poisoning because the treatment is very unlikely to be successful. Cattle with lead toxicity are not fit for human consumption because high lead levels can be passed to consumers through the meat. In fact, up to a year or longer after a confirmed lead exposure, cattle that were possibly exposed to lead should have a blood sample tested before they are sold into marketing channels leading to human consumption because they may be carrying high levels of the dangerous mineral. There is no known use for lead in the human body and no acceptable level in the human diet because of its severe negative effects; therefore, every attempt must be made to keep lead out of the food chain.

If lead poisoning is suspected, immediately remove all cattle from the pasture. Treatment begun before signs of disease are noticed may be helpful, and you and your veterinarian may choose to treat young calves that were exposed to lead but that are not showing signs of poisoning. There are treatments given by stomach tube to try to flush the lead out of the digestive tract (magnesium sulfate – Epsom salts), high doses of thiamin (a B-vitamin), and a compound administered into the bloodstream (calcium-EDTA) to tie-up lead circulating in the blood. The treatment of lead poisoning requires multiple treatments per day over several days of therapy and calcium-EDTA administered into the blood is expensive.

This serious problem can be prevented by making sure that your cattle cannot come into contact with old cars or farm equipment, batteries, construction materials, lead paint, or old burn piles. Many times, old equipment or trash piles have been present in a pasture for many years with no problems and then because something disturbs the trash, a fence is moved, or younger cattle are placed in the pasture, cattle can suddenly die of lead poisoning.

Research and Innovation

Bob L. Larson, DVM, PhD

Beef Cattle Institute

Kansas State University

Changes in the tools and solutions available to address beef cattle health and production concerns are being driven by both time-tested and new areas of research and innovation. The advances being made in genetics, geographic information systems, nanotechnology, and computing power are exciting and provide researchers with new tools to learn about cattle nutrition, reproduction, grazing, health, and behavior. But all innovations are built on foundational knowledge of animal husbandry and the daily needs and characteristics of cattle.

Genomics and related research areas such as proteinomics, lipidomics, and other “omics” are used to study the molecules that are inside cells including DNA, RNA, proteins, fats, and carbohydrates. New laboratory tools are being developed to allow animal and veterinary scientists to investigate how different cattle respond to different nutrients, disease challenges, and environmental factors at the cellular level.  These types of studies were not possible just a few years ago, and it is hoped that learning about what is happening in the cells will help explain differences we see in living cattle.

Geographical Information Systems (or GIS) uses maps and other data to ask questions about the characteristics of specific places and the animals, plants, and environment associated with those places. From GPS and GIS technologies in our cars, phones, and farm equipment, “precision agriculture” is changing the way food producers think about using land, animals, labor, and other resources so that each square-foot of land or each individual animal is managed for its own optimal production, rather than for optimal production at the herd or field level. GIS also allows researchers with different areas of expertise such as soil health, forage production, water quality, plant health, cattle health and growth, meat science, and economics to add “layers” to the information for each area and animal on a ranch so that scientists can study complex trade-offs between different aspects of cattle production.

Nanotechnology and nanoscience is the use and study of extremely small things (less than 100 nanometers in size) created to serve many different purposes. To understand how small these devices are – there are over 25 million nanometers per inch, so more than 250,000 of the largest nanodevices could fit in an inch. New microscopes that allow scientists to see things as small as an atom have allowed this area of research and innovation to move rapidly from science fiction to marketable products. Nanodevises could be used to deliver small doses of drugs to parts of the body that are affected by disease and to avoid parts of the body that could have a toxic reaction. Other nanotechnology will likely be used to deliver nutrients, detect disease, and improve meat packaging.

All of these areas of innovation are made possible by rapidly increasing computing power which takes the relatively simple task of doing math problems and allows scientists to ask deeper questions about nature and cattle production. The amount of numbers that are generated by studies using genomics (and other “omics”), GIS, and nanoparticles can only be organized and evaluated using computing speed that was not available until recently. New ways of collecting and storing data and doing math are being developed to keep up with growing amounts of information generated from innovations that are investigating both smaller and larger environments associated with cattle production.

It might be easy to become excited (or appalled) by the innovations that are changing the way scientists do research; but as I look at those who are doing the most beneficial projects, I see animal and veterinary scientists who combine an appreciation for cattle and cattle producers with their knowledge of the latest tools to investigate the mysteries of biology. It seems to me that the more we learn about cattle the more we realize how much is still hidden. By appreciating how amazing cattle and the rest of biology are, scientists take small steps toward understanding the things we see every day – cattle eating grass, growing muscle, becoming pregnant, being challenged with disease, recovering from disease, and serving an important and complex role in the earth’s ecosystem. Although the tools that are the result of and drivers of innovation tend to be complex, the questions that drive cattle research are straightforward and similar to the questions asked by animal and veterinary scientists for generations: How to best utilize forage resources? How to meet the nutrient needs of cattle throughout their life? How to identify individuals with the most valuable genetic traits? How to grow and harvest muscle tissue that makes the most desirable food? And, how to diagnose and treat animals that become sick? In my opinion, the tools aren’t what makes a good scientist, my science heroes have a love for biology, for cattle, and for discovery that makes them want to continue learning throughout their life and to serve cattle and cattle producers by finding solutions to life’s everyday challenges.

Animal Welfare and Consumer Relations

Bob L. Larson, DVM, PhD
Beef Cattle Institute
Kansas State University

Providing a safe and healthy environment for cattle is not only the foundation for good animal welfare and efficient production, but is also necessary in order to maintain a positive image of cattle production for consumers.

Day to day care for cattle requires that producers meet each herd’s nutritional and health needs as well as provide housing and handling facilities to ensure their safety and welfare. Cattle are able to eat a wide variety of forages and feeds to meet their nutritional needs. When cattle of almost any age and stage of production are housed on green, growing pastures, they are not likely to require a great deal of additional feed. However, salt and other minerals are required in all cattle diets, and growing calves and yearlings, and lactating cows and heifers require diets that are higher in energy and protein than dry cows and bulls. Cattle grazing dormant forage or being fed harvested hay or other forages may require a supplemental feed or forage that has higher concentrations of energy or protein than the base forage. This supplement may be in the form of high quality hay, grain or grain-byproducts, or other processed feeds. Evaluating weight gain in growing animals and body condition in mature animals provides cattle producers with a simple measure of whether or not a diet is meeting the energy and protein needs of their cattle.

Providing plenty of readily accessible water is another key component in meeting the daily needs of cattle. While well-informed people may disagree about how long cattle can be held away from water without adversely affecting their health and welfare, the basic principle that cattle need plenty of clean water is undisputed. The time of year, the number of cattle, and whether the cattle are near the water source throughout the day or only part of the day all impact the amount of space and the flow rates required. Hot temperatures in summer increase the daily requirement for water and the potential for freezing increases the risk of failed water delivery in the winter. Range situations when cattle are only near the water source for a limited amount of time each day require greater one-time access space and water reserve than cattle housed in small pastures or drylots with continual access to water. Stock tanks or waterers that are not cleaned can result in reduced water intake; and mud, erosion, or other obstacles that make it difficult for cattle to approach a water source can lead to health and welfare problems.

Beef cattle are nearly always housed outside on pastures or drylots which usually means that air quality and sanitation is good. However, cattle housed outdoors in most parts of North America must contend with extremes in temperature and humidity during certain times of the year. Extremely cold and hot temperatures can cause severe stress and health problems. When rainfall is heavy, excessive mud can prevent comfortable resting and be a barrier to feed and water access. Making sure that cattle are protected from extreme wind chills by the use of natural or man-made wind breaks and providing access to shade or other relief during periods of high heat index are important considerations for cattle housed outdoors. In addition, all fences, feed bunks, water troughs, and handling facilities should be designed and maintained so that cattle are not likely to injure themselves and so that the facilities can be used as they were intended. Everyone who works with cattle should understand and implement low-stress handling techniques to minimize the risk of cattle becoming injured or exhausted during handling. To implement low-stress handling, a ranch must have appropriate facilities and well-trained cowboys or animal handlers.

Providing cattle with proper diets, treating for internal parasites (worms) and external parasites (flies, lice, ticks, etc.), protecting the herd from avoidable contact with disease carriers, and using appropriate vaccines not only helps to protect the health and welfare of cattle, but supports high productivity of the herd. By concentrating on nutrition, sanitation, parasite control, biosecurity, and vaccination, ranchers can ensure that they are focusing their efforts to meet the health and welfare needs of their herd.

In addition to meeting cattle’s daily needs, every cattle producer must be prepared for potential challenges such as drought, hurricanes, tornadoes, floods, fire, blizzards, and other natural or man-made disasters. While most disasters cannot be avoided, those that are reasonable possibilities should be thought about ahead of time. Planning for ways to provide feed, water, and shelter to the herd as soon after a disaster as possible guarantees that animal welfare will be minimally compromised.

And finally, every cattle producer needs to have a plan for how he or she will deal with a severely injured or ill animal. Although providing an excellent environment with appropriate diets and a good herd health program will minimize the risk of disease and injury, all ranchers know that recognizing when an animal should be euthanized is critical to ensuring the humane care of their herd. Appropriate methods to euthanize (put to sleep) cattle have been recommended by the American Association of Bovine Practitioners and the American Veterinary Medical Association. Every ranch should have at least one person who is trained to appropriately euthanize cattle or should have access to a veterinarian to perform this important function.

Time-tested principles of good cattle management are the keys to assuring the health and welfare of cattle herds. Increasingly, consumers are also interested in knowing that cattlemen are concerned about the welfare of their animals. It is becoming very important that you have a management plan that you can share with anyone who asks so that beef consumers can be assured that you also value the health and welfare of your herd.