Mineral Nutrition for Grazing Beef Cows: Intake and Quality

When beef cows are grazing over the next few months, nutrient requirements for energy and protein are generally met by the forage, and thus vitamin and mineral supplementation is the primary nutritional concern. Most producers provide free choice mineral to cows during this time and assume that it is providing adequate amounts of the necessary minerals. However, there are some important factors to consider to ensure mineral requirements are met.

First, and most important is mineral intake. Cows do not consume free choice mineral consistently throughout the summer grazing season. Some believe that cows will consume what they need, but that is not the case. Salt intake is the driving factor affecting mineral intake. If cattle are consuming significant amounts of salt in the forage, then they will decrease intake of high salt mineral and vice versa if they are consuming small amounts of salt in the forage. Adjusting the amount of salt in the mineral is the best way to regulate intake, and if plain white salt is provided mix it with the mineral otherwise cattle will consume the salt instead of the mineral.

Availability and location of clean water can also impact mineral intake. Mineral supplements generally have a high salt content, and cattle will want a drink after consuming mineral. And may stop consuming mineral sooner if water is not readily available. Placing mineral feeders relatively close to water sources can help if mineral intake is less than desired, but having mineral feeders too close to loafing areas can result in overconsumption of mineral.

The form mineral is provided can also affect intake. Cows will generally consume less mineral per day when in block form than in loose form just for the simple fact that the amount of mineral consumed per minute is lower with blocks. It is important to provide several blocks at once so multiple animals can consume mineral at the same time. Also, lower intake of mineral blocks means that the mineral concentration in the block should be increased accordingly. Blocks may be a good option during times of the year when cattle want to overconsume loose mineral. Mineral tubs on the other hand are consumed in greater amounts than loose mineral by cows, generally by design as tubs usually provided added protein and sugars to aid in digestion of more mature forages. However, the high palatability of tubs can easily result in overconsumption.

Individual cows also do not consume the same amount of mineral with some cows consuming less and some cows consuming more than desired. In a recent study at the USDA-ARS For Keogh Livestock & Range Research Laboratory, there was a 3-fold difference in mineral intake among cows in the herd. Currently, very little is known about the variability in mineral intake among cows and the reasons this variability exists. In this study there was no statistical difference in calf weaning weight or postpartum interval between cows consuming the most versus the least amount of mineral, but there appeared to be a linear trend that as cows consumed more mineral, calf weaning weight decreased. There could be several reasons for this that need to be explored before management strategies can be developed.

The most important aspect of mineral intake is to monitor intake. Adjustments to salt content or mineral form cannot be made accurately if the current level of mineral intake is not known. The date mineral is delivered, amount of mineral delivered, and the number of cows in the herd should recorded to compute the average daily mineral consumption. Mineral intake can then be managed accordingly.

The second factor of mineral supplementation is the quality of the mineral, which includes concentration of individual minerals in the supplement, bioavailability of the mineral sources and mineral deficiencies of the forage, all of which affect the ability of the mineral supplement to meet the mineral requirements of the cow herd. Soil mineral content and plant availability, forage species, and forage maturity affect the mineral content of the forage consumed by the cow. Different regions of the US differ in mineral content of soils resulting in different mineral content of forages grown in that region. Other characteristics of the soil, such as clay content and pH, also affect the availability of soil minerals for uptake by the forage plant. Thus, mineral supplements should be formulated for the region of the country where they will be used.

Forage species also differ in mineral content even when grown in the same soil. In broad terms, legumes are different than grasses, and cool-season grasses are different than warm-season grasses. For all forage species, mineral content is generally greater in lush growing plants than more mature plants. Additionally, more mineral is associated with the plant cell wall, which is the less digestible fraction, as the forage plant matures. The proportion of individual minerals also changes as the forage plant matures. Thus, the concentration of individual minerals in the supplement should change in different times of the year.

There are several sources of minerals that can be used in manufacturing a mineral supplement: oxide, sulfate, chloride, and organic. These sources differ in bioavailability, which is the ability of the mineral to be absorbed and function in the body. Generally, organic sources are the most bioavailable, but the increase in bioavailability compared to the other sources is not equal among mineral elements. For example, organic selenium is 40% more bioavailable than selenite, but organic manganese is only 25% more bioavailable than manganese sulfate. Sulfate and chloride sources have similar bioavailability, and oxide sources have very low bioavailability with the exception of magnesium oxide, which is similar to magnesium sulfate or magnesium chloride. Knowledge of the source of the mineral element in the mineral supplement can be important, especially in areas where mineral antagonists are prevalent in forage plants.

There are several factors to consider and manage when it comes to mineral supplementation of grazing beef cows. Make sure that the mineral supplement is formulated for the soils and forages in the appropriate region of the US. Monitoring mineral intake is the most important aspect because even the best formulated mineral cannot meet cow requirements if the mineral is not consumed in the proper amount.

AI Programs Expectations, Heifer and Cow Synch Programs, Sexed Semen in Beef Cattle

Welcome to BCI Cattle Chat!  Please click on any links below to be taken to sources mentioned in the podcast. Keep an eye out for news regarding the podcast on Facebook, Twitter, and Instagram.

3:13 AI programs expectations

11:04 Heifer and cow synch programs

16:44 Sexed semen in beef cattle

Guest: Sandy Johnson, extension beef specialist
Beefrepo.org 

For more on BCI Cattle Chat, follow us on Twitter at @The_BCIFacebook, and Instagram at @ksubci. Check out our website, ksubci.org. If you have any comments/questions/topic ideas, please send them to bci@ksu.edu. You can also email us to sign up for our weekly news blast! Don’t forget if you enjoy the show, please go give us a rating!

Role of Research for the Future of Beef Production

Known cattle production efficiency and health problems, new challenges and opportunities, changing economic and societal situations, and human curiosity all drive the need for beef cattle research. Recognizing the need for research means that cattle producers, scientists, and many other stake-holders agree that there are opportunities to improve diverse areas of cattle health and well-being, production, and economics. From a veterinary perspective, investigations of management, genetic selection, and technology interventions to increase reproductive efficiency, improve forage utilization, avoid disease, and enhance disease treatment effectiveness are exciting areas of research. Because of ongoing research, veterinarians and beef cattle producers can look forward to having more information and new tools to improve cattle health and well-being, production efficiency, and long-term sustainability.

Careful and accurate observation of cattle and their environments plays an essential role in scientific research, but observation alone will not lead to new understanding about how to improve cattle production. Research combines careful observation with specific strategies to account for the natural variation that occurs when different individual cattle are treated identically, and with methods to limit unintended biases from interfering with a true interpretation of how cattle behave and respond to different environments and treatments.

 The reason that cattle research must be carefully planned is that cattle health and well-being and production efficiency are influenced by a complex interaction of many biologic and economic factors. The biologic factors include: cattle genetics, forage quality and availability, the presence and types of different disease risks, the varying impact of temperature, humidity, and other environmental features on different cattle, how cattle respond to the stresses they encounter, and many other factors. Observations of relatively few animals or observations taken over a short period of time often fail to allow a person to accurately understand the many factors that interact to cause an outcome.

Because of these challenges, even well-planned research projects can only answer one or two fairly limited questions at a time. But a long-term approach to solving the important questions facing cattle veterinarians and producers through a series of studies carried out on a variety of cattle types, ages, and environments, slowly allows researchers to build an understanding of the interacting factors that can be managed to improve cattle production.

Some of the interesting areas being researched now include: investigations into the role that genetics plays on which cattle are most likely to be resistant to various diseases, research comparing the ability of diagnostic tests to more accurately identify cattle that can spread disease to other animals, and comparisons between different methods of preventing or treating diseases that commonly affect cattle. In addition, there are very interesting investigations of how cattle management can enhance utilization of available forages, and how nutrition at one stage of life affect other stages of life. There are also exciting areas of research to improve reproductive efficiency of cattle by investigating more accurate ways to sort bulls into high- and low-reproductively sound classifications, to enhance the fertility of cows, and to reduce the risk of abortion in pregnant cows. Many studies are looking for ways to utilize new technologies such as computers, genetic testing, GPS tracking, and miniature robots to improve cattle production. Other areas of study include investigations of cattle behavior, grazing patterns, rumen function, growth efficiency, response to vaccinations, and resistance to disease based on time-tested production methods.

Regardless of the area being studied, research is a slow, step-by-step process with very few leaps in new knowledge. But the results of multiple well-planned research studies evaluated over time and across different production situations gradually adds to our understanding of the factors that impact cattle health and well-being and production efficiency. Current cattle producers and veterinarians benefit from many decades of research that has provided valuable strategies and tools that are used daily. The research that is being conducted today will provide additional breakthroughs in the coming years.

Food Animal Veterinary Certificate/ Veterinary Training Program for Rural Kansas, Should You Perform a BSE on a Mature Bull, Veterinary School Advice

Welcome to BCI Cattle Chat!  Please click on any links below to be taken to sources mentioned in the podcast. Keep an eye out for news regarding the podcast on Facebook, Twitter, and Instagram.

4:37 Food Animal Veterinary Certificate/ Veterinary Training Program for Rural Kansas

9:20 Should you perform a BSE on a mature bull?

17:10 Veterinary school advice

For more on BCI Cattle Chat, follow us on Twitter at @The_BCIFacebook, and Instagram at @ksubci. Check out our website, ksubci.org. If you have any comments/questions/topic ideas, please send them to bci@ksu.edu. You can also email us to sign up for our weekly news blast! Don’t forget if you enjoy the show, please go give us a rating!

After the Chat: Bacterial Vaccine Efficacy

In After the Chat, the BCI experts go in deeper about topics from this week’s episode, but also other ideas:

This episode contains a follow on bacterial vaccine efficacy.

For more on BCI Cattle Chat, follow us on Twitter at @The_BCIFacebook, and Instagram at @ksubci. Check out our website, ksubci.org. If you have any comments/questions/topic ideas, please send them to bci@ksu.edu. You can also email us to sign up for our weekly news blast! Don’t forget if you enjoy the show, please go give us a rating!

Small Calves, Peak Nutritional Needs, Clean-Up Bull Planning, Manheimmia on Environmental Surfaces

Welcome to BCI Cattle Chat!  Please click on any links below to be taken to sources mentioned in the podcast. Keep an eye out for news regarding the podcast on Facebook, Twitter, and Instagram.

2:21 Small calves

7:38 Peak nutritional needs

13:56 Clean-up bull planning

21:08 Manheimmia on environmental surfaces
Read the article here

For more on BCI Cattle Chat, follow us on Twitter at @The_BCIFacebook, and Instagram at @ksubci. Check out our website, ksubci.org. If you have any comments/questions/topic ideas, please send them to bci@ksu.edu. You can also email us to sign up for our weekly news blast! Don’t forget if you enjoy the show, please go give us a rating!

Limit Feeding Cows in Drylots

Dry weather across most of the central plains since last fall is creating signals, that a major drought may be on the horizon for this grazing season. The reliance on pasture of most cow herds means that some hard decisions will likely need to be made. The primary decision revolves around feed sources to replace hay or pasture or stretch hay or pasture. Several commodities can be used to replace or stretch hay and pasture; mostly by-products from grain milling.

Two key nutrients are total digestible nutrients (TDN) and crude protein (CP). TDN is the measure of energy used with beef cows, and is the nutrient needed in greatest quantities to maintain performance. CP is the next nutrient needed as far as quantity. Feeds have different concentrations of TDN and CP, and have different costs. Figure 1 illustrates the cost per unit of nutrient of common commodities, which is an effective way to compare feed cost. Hay at $100/ton has the lowest cost per unit of TDN and CP. However, when hay reaches $200/ton, which may happen in severe drought situations especially if trucking long distances, it has the greatest cost per unit of TDN and second greatest cost per unit of CP. Additionally, hay supplies may be limited even if hay is the cheapest source of nutrients.

Currently, corn at $6.50/bu is the least expensive source of TDN followed by soybean hulls at $210/ton and dried distiller’s grains at $280/ton. Dried distiller’s grains is also the least expensive source of CP making it a valuable feed. Therefore, a mixture of corn, soybean hulls, and dried distiller’s grains would be an economically and nutritionally viable option to replace or stretch hay or pasture.

A 1300-lb cow in late lactation requires about 14 lb of TDN and 2.10 lb of CP per day. A mixture of 15% dried distiller’s grains, 20% corn, 35% soybean hulls, and 30% hay fed at 20 lb/day (80% of ad libitum intake) would meet the TDN and CP requirements of the cow. The calf will consume about 4 lb/day of hay or pasture for a total of 24 lb/day. If calves are weaned early at 4 months, 15 lb/day will meet the TDN and CP requirements of an early gestation, dry cow, but then the calf will eat 7 lb/day of mixed ration to gain 2 lb/day for a total of 22 lb/day.

If the price of hay is $100/ton, it is more economical to feed the lactating cow with a nursing calf at $2.11/day, but if the price of hay is $200/ton, it is more economical to wean the calf early and feed a dry cow plus calf at $2.49/day. If the price of hay is $150/ton, then both management options cost the same. This economic calculation is based on the prices of feeds used, and the tipping point will depend upon local hay and commodity prices.

Even though feeding commodities to beef cows and calves can be an economically viable option, it requires the correct management. Feeding large amounts of commodities to beef cows who have full access to pasture or hay will not save much hay and result in greater feed costs. The cost savings is in the fact that less total feed (reduction in hay intake) can be fed to maintain cow performance, which requires limiting access to pasture or hay. It does not require a fenceline feedbunk and mixer wagon. Use the resources you have such as labor, hay intake can be limited by restricting access to the round bale feeder by moving cows in and out of the pen with hay feeders. Early-weaned calves also require more managerial skills in that they are more susceptible to disease and require daily feeding and observation. The rumen of these young calves is not developed enough to effectively digest long-stem hay, and they require moderate energy diet based on grains and commodities to perform well.

Finding alternative feed sources during a drought can be challenging especially if the drought is widespread and hay has to be hauled long distances. Grains and byproduct commodities are viable alternatives that can be used to maintain performance of the cow herd, but feed costs are going to be greater. Additionally, limit feeding moderate concentrate diets to beef cows and managing early-weaned calves requires the correct facilities and managerial skills.

Figure 1. Cost per unit of total digestible nutrients (TDN) and crude protein (CP), and cost per day to maintain 1300-lb cow for common feedstuffs.

Assessing the Sustainability of Beef Cattle Ranching

A recent paper synthesized ranch sustainability indicators from multiple assessments to develop an overall set of indicators. The indicators include environmental, ecological and socioeconomic aspects of sustainability. The environmental indicators include things like soil carbon and stability, plant productivity, water quality and retention and condition of riparian systems. These indicators are highly influenced by grazing management. Several forms of grazing management exist that can improve these indicators; most involve some form of rotation so that land is not overgrazed leading to bare soil and that plants have rest to recover and develop strong root systems.

The ecological indicators include plant, animal and bird diversity. Again, these indicators are influenced by grazing management, where a diversity of plant species, plant densities and plant heights provide habitat for a diversity of animal and bird species. Also, fire regime is important in controlling the diversity of plant species, again providing habitat for different animal and bird species.

Finally, the socioeconomic indicators include rancher connection with the community, rancher satisfaction, livestock and non-livestock income, forage utilization and capacity to experiment. Many facets of ranch management affect these indicators such as size of the ranching operation, rancher ability to participate in community organizations and geographic location of the ranch. These indicators are the least thought about aspects of ranch sustainability, but are some of the most important because most of all ranching is a livelihood and way of life for people that brings meaning to their lives.

Collectively, these indicators provide a well rounded means of assessing ranch sustainability and communicating all the important aspects of sustainability to the public; not just the environmental aspect.

Cold Weather Concerns

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

A high percentage of the U.S. beef herd resides in areas of the country where moderately to extremely cold winter temperatures are common. By planning for winter weather, ranchers can avoid being caught off-guard by extreme events and can manage the typical winter conditions so that cattle do not have to continually utilize body fat as an energy source to keep warm – leading to excessive loss of body condition.

Situations that are most likely to cause cold stress are: cattle with thin fat cover and short hair coats (due to movement from a warmer environment to a colder environment; or extremely cold temperatures early in the fall/winter season), cattle with wet hides, or high wind speed accompanying cold temperatures. Wind chill is a better predictor of cold stress than temperature alone because cold wind draws heat away more quickly than still air at the same temperature. Wet or mud-caked hair losses its ability to insulate the animal and a wet winter hair coat only provides as much protection from the cold as a typical summer hair coat. If cold wind is combined with a wet hair coat (as can occur during a winter storm), the effects can be very profound.

Adult cattle with a dry hair coat, adequate body condition, and abundant, adequate-quality forage can withstand most winter situations, especially if they have the ability to find protection from wind and have been exposed to moderately cold condition for several weeks which allows them to acclimate by growing a thick winter hair coat and increasing feed intake. As temperatures drop, cattle increase heat production which means that the number of calories they need for maintenance increases. This increase is met by consuming more feed and moving it through the digestive tract faster, but the cost of this faster movement is that feed is not digested as fully. The effect of needing increased calories for maintenance at the same time that feed digestibility is decreasing means that if cows do not have access to plenty of digestible feed, they will have to “burn” body fat as a calorie source. Another factor that can limit feed intake in winter conditions is if water sources are frozen or unavailable. If feed intake cannot keep up with energy demands, and body fat is mobilized to meet energy demands, then the cows will have less fat insulation and will be more susceptible to cold temperatures – causing a viscous cycle that can lead to cold stress and even more weight loss.

Cold weather brings a special concern with bulls because of the potential to have frostbite damage to the scrotum and testicles. It is very important that bulls have protection from the wind and adequate bedding if they are housed on concrete or dirt.

Cold temperatures have the greatest potential to cause serious problems in young calves, particularly calves in the first day of life. Because calves are born wet, have thin skin and very little body fat, they lose body heat very rapidly and if they are not able to become dry, can quickly become severely cold stressed. Contact with snow or wet ground will increase the amount of time that a calf stays wet and in danger. Body temperature of newborn calves can drop to dangerously low levels in 3 hours or less.

Calves are born with a body temperature of about 100˚F. When exposed to a cold environment, calves are able to produce heat in two ways, shivering and the heat production of brown fat (fat that surrounds the kidneys of a new-born) and they can conserve heat by reducing blood flow to the body surface and extremities (feet, ears, etc.). In early stages of cold exposure, calves will shiver vigorously and have a fast heart rate and breathing rate. If that does not keep the body temperature up, the calf’s body sends less blood to feet, ears, and nose in an effort to minimize heat loss. Severe cold stress occurs when the body temperature drops below 94˚F. At this temperature, the brain and other organs are affected and the calf becomes depressed, unable to rise, unwilling to suckle, and will temporarily lose the ability to shiver. The good news is that if the calf can be warmed-up and its body temperature can begin to rise, the shivering response will return and the core body temperature will slowly increase.

During periods of cold or wet weather, newborn calves (less than 1 to 2 days of age) should be checked every few hours with a thermometer and any calf with a below-normal temperature, even if it appears OK, should be warmed. Calves suffering from cold stress must be warmed so that body temperature can rise above 100˚F. If body temperature has not dropped too far, putting the calf in the cab of a pickup out of the wind and rain or snow will warm the calf. In more severe cases the calves can be placed in warm water, specially designed warming boxes, or near a heat source such as an electric blanket, heat lamp, or hot water bottles. To avoid skin burns, the heat source should not exceed 108˚F. In addition to an external heat source, cold-stressed calves should be fed warm colostrum, milk, or electrolyte fluid with an energy source using an esophageal feeder. 

Prevention of cold stress involves management to ensure that calves can be born in a short period of time and both the calf and dam can stand shortly after calving so that they can bond and the calf can begin suckling. Anything that prolongs calving or reduces the chance that a calf will suckle soon after birth should be addressed by management changes. Calving difficulties are minimized by proper heifer development, proper bull selection for calving ease, and proper nutrition so that heifers and cows calve in a body condition score of 5 to 6 on a 9-point scale. Cows with large teats or that are not attentive mothers should be culled.

Use of pasture as the primary forage source during calving encourages cows to keep spread apart and minimizes development of muddy areas. If the herd forage plan includes feeding hay, consider feeding hay in early to mid-gestation and saving stockpiled pasture for the calving season. If supplemental hay and grain are fed during calving, these should be provided at locations that are separate and distant from water sources and windbreaks. I discourage the use of bale rings in calving and nursery pastures and suggest that if using large round bales, they be unrolled and the feeding area changed with each feeding. Unrolled bales will have greater hay waste, but reduced chance for mud caused by concentrating the herd into small feeding areas, and unrolled hay provides bedding for newborn calves so that they are not in direct contact with the ground.

In addition to monitoring the weather forecast for severe winter weather events and to be alerted to times when additional feed is needed, minimizing the effects of cold temperatures on newborn calves involves planning ahead and considering calf comfort and protection when making heifer development, bull selection, nutrition, and pasture management decisions. Making sure that cows will have adequate access to forage and water even in situations with significant snow cover is necessary to provide sufficient calories to maintain body fat and heat production. And, protecting the cowherd (and bulls) from winter wind and providing bedding if on concrete or mud/dirt will minimize the effects of severe weather.

Listener Question: Post-Drought Management, Eliminating Pregnancy Loss, Internal Parasite Treatment

Welcome to BCI Cattle Chat!  Please click on any links below to be taken to sources mentioned in the podcast. Keep an eye out for news regarding the podcast on Facebook, Twitter, and Instagram.

3:54 Listener question: post-drought management

9:42 Eliminating pregnancy loss

17:13 Internal parasite treatment: topical vs. injectable vs. oral

Special Guests: Jeba Chelladurai and Brian Herrin, Parasitology at K-State College of Veterinary Medicine

For more on BCI Cattle Chat, follow us on Twitter at @The_BCIFacebook, and Instagram at @ksubci. Check out our website, ksubci.org. If you have any comments/questions/topic ideas, please send them to bci@ksu.edu. You can also email us to sign up for our weekly news blast! Don’t forget if you enjoy the show, please go give us a rating!

Climate-neutral Beef: What does it mean for the producer?

Recently, the National Cattlemen’s Beef Association committed the U.S. beef industry to be climate neutral by 2040, but what does that really mean, how are we going to get there, and what does it mean for the individual producer? Climate neutral is different than carbon neutral in that carbon neutral indicates that carbon emissions are equal to carbon sequestration whereas climate neutral indicates no net global warming effect. Beef cattle most probably can never be carbon neutral due to the biogenic carbon cycle (Figure 1) because it would require carbon sequestration to be as great as the carbon synthesis in plants every year. However, beef cattle can be climate neutral because carbon/methane emissions are part of the biogenic carbon cycle rather than a permanent addition to the atmosphere. If methane emissions and photosynthesis are in equilibrium then there is no net global warming.

Aren’t we already in equilibrium? Short answer is no. It takes a decade or more of static cattle numbers and methane emissions before the cycle is in equilibrium, and beef production results in other gases, carbon dioxide and nitrous oxide, that increase global warming. Over the last 30 to 40 years, the beef industry has reduced the carbon emissions intensity (carbon per unit of beef) primarily through increased efficiency (lesser inputs per unit of beef) and diluting maintenance requirements of the cow herd with heavier, faster growing calves. U.S. beef industry is the most efficient production system in the world, but we are maximizing growth and size, and so future reduction in global warming potential will need to come through reductions in total carbon emissions per animal.

What does this mean for the rancher? The reduction in carbon emissions and global warming potential will come from application of several management practices and technologies. For example, improved grazing management and use of cover crops will increase soil carbon sequestration, but also improve soil health and forage/crop productivity. Many new feed additives are being developed to reduce methane emissions, some with potential to increase feed efficiency. Genetic tools will allow selection of animals to reduce maintenance energy requirements, and genetically engineer will produce animals resistant to disease. These practices and technologies and many others will be available to ranchers to reduce carbon emissions and global warming potential, but importantly these practices and technologies will improve economics of beef production. Achieving the climate neutrality goal will be challenging, but will spur many new advancements that will make beef production better for the rancher, consumer and environment.

Figure 1. Illustration of the biogenic carbon cycle of all ruminant animals including cattle. Credit to University of California-Davis CLEAR Center.

Managing Plant Biodiversity to Increase Ranching Profits

Recent cow-calf model analysis from the Beef Cattle Institute at Kansas State University indicates that forage yield per acre is a very important driver of profitability; more so than increased reproductive efficiency, decreased maintenance energy requirements or increased forage digestibility (Figure 1).  Increasing reproductive efficiency reduced replacement heifer costs. Decreasing maintenance energy requirements or increasing forage digestibility increased calf growth and calf revenue. But the reduction in replacement costs or increase in revenue was not as great as the reduction in winter feed costs from more forage yield and longer grazing season. Thus, increasing forage yield per acre is one of the most powerful management tools to increase cow-calf profitability.

Plant biodiversity is beneficial for grassland ecosystems by providing food and habitat for wildlife and improving nutrient cycling, soil organic matter, water infiltration, and total biomass production to name a few. Monocultures are easier to manage but may be hurting the productivity of the grassland and making it less resilient to drought and heavy grazing. Mixtures of forbs, legumes, and grasses can boost grassland productivity in the long-run and are more sustainable ecosystems.

When we think of cattle grazing pasture or rangeland, we picture cattle consuming grass, but cattle consume much more than grass. Many plants/forbs considered weeds such as ragweed actually have better nutritional profile than many grasses, and cattle will eat many of them at different stages of plant development. Some of these plants have large tap roots that bring water and nutrients up to the soil surface where the fibrous roots of grasses have access. Non-grass plants can grow between clumps of bunch grasses and provide increased forage through both primary production but also by improving nutrient cycling and soil function for growth of the whole plant community. Additionally, mixtures of grass species that have primary growth at different times of the year such as fescue and crabgrass also increase grassland productivity. The difference in timing of primary growth allows nutrient cycling in a grazing system as the defecated nutrients from one grass fertilize the other.

Not all forbs are consumed by cattle, but forbs that fix nitrogen can be beneficial by adding nitrogen to the soil through decomposition even when not consumed. However, some forbs such as sericea lespedeza can have negative effects on overall grassland productivity, and must be kept in check.

Herbicide sprays often kill both harmful (e.g., sericea lespedeza) and beneficial (e.g., Illinois bundleflower) forbs and legumes, which may reduce overall productivity rather than increase it. Assessing the plant species composition of harmful to beneficial forbs is critical to evaluate whether herbicide application will be cost effective. Other tools such as prescribed burning can also be used to manage the plant species composition without detrimental effects on all forbs and legumes. The take-home message is that a clean field of grass is likely not the most productive or profitable, but neither is a field of weeds: the goal should be to balance the species composition to maximize consumable biomass over the long term.

Figure 1. Correlation of management factors with overall cow-calf profitability. The larger the difference from 0 the more important the management factor to profitability.

Episode 1- Sustainability Definition, Cattle Greenhouse Gases, Small and Family Farms

In this episode, we go into what sustainability is and the different components of sustainable beef production, cattle’s contribution to greenhouse gas emissions, and what family and small farms are in the United States. These podcasts are sponsored by Beef Checkoff. Follow BCI on Instagram, Facebook, and Twitter. If you have any questions email us at bci@ksu.edu.

Nutritional Technology Impacts Animal Health and Social Sustainability of Beef Production

Animal health and welfare are important components of social sustainability. In the beef industry, bovine respiratory disease complex is likely the largest issue, and also influences antimicrobial stewardship. Nutritional stress when adapting cattle to high grain diets occurs in the form of subacute acidosis predisposing cattle to other health challenges such as bovine respiratory disease. Acidosis occurs from overproduction of lactic acid from rapid fermentation of starch, and the slow adaptation of cattle to a high grain finishing diet is necessary to allow the population of lactic acid utilizing bacteria in the rumen that keep the lactic acid concentration low and rumen pH high.  Subacute rumen acidosis has been linked to the release of lipopolysaccharides from dead bacteria causing inflammation that may predispose cattle to other health issues. Early bovine respiratory disease research indicates that high concentrate starting diets and lack of adequate roughage intake during the receiving period, both of which could result in subacute rumen acidosis, increase the incidence of respiratory disease.

A major lactic acid utilizing bacteria in the rumen is megasphaera elsdenii.  Inoculation of cattle with M. elsdenii when introducing a high starch diet, stabilizes rumen pH, prevents subacute rumen acidosis, and allows stepping cattle up to the finishing diet quicker. Additionally, inoculation of feedlot cattle on arrival can reduce respiratory morbidity, particularly in higher-risk calves, although the number of studies is limited (Figure 1).  Clinical signs of rumen acidosis and respiratory disease are somewhat similar and misdiagnosis can occur. Thus, the reduction in respiratory morbidity could be those calves with rumen acidosis being misdiagnosed as bovine respiratory disease.  But either way, inoculation of cattle with M. elsdenii at arrival can reduce animal disease and antimicrobial use. Nutritional technology plays a role in animal health-improving antimicrobial stewardship and social sustainability.


Figure 1. Prevalence of bovine respiratory disease in calves (1 study) or yearlings (2 studies) receiving megaspheara elsdenii orally at arrival (ME) or not (Control). Data from McDaniel (2009; https://krex.k-state.edu/dspace/handle/2097/1666) and Miller et al. (2013; Bovine Practictioner 47:137)

Changing the Timing of the Spring Calving Season can Increase Economic Sustainability

Choosing the optimum time to calve beef cows involves thinking through a multitude of factors such as potential for extreme weather, availability of grazed forage, marketing and seasonality of calf prices, and availability of labor. Thirty years ago, the logic used for choosing a calving season focused on maximizing calf nutrient intake. At about 3 to 4 months of age, the calf’s nutrient requirements exceed the cow’s milk production, and thus calf nutrient intake and growth could be increased by coinciding this time with the time of highly nutritious forage. In order to accomplish, cows needed to calve in February and March for most latitudes. However, this results in increased feed costs because lactating cows consume more harvested forages and the nutritive value of harvested forages is generally not adequate to meet the nutrient requirements of early lactation cows. Thus, supplemental feed is usually necessary to keep cows in adequate body condition (≥ 5) prior to breeding to ensure high pregnancy rates.

Matching the calving season with the onset of green pasture synchronizes the high nutrient demands of the cow during early lactation and breeding with the time of maximum forage nutritive value. By doing this, stockpiled forages and crop residues can meet the nutritional requirements of cows through December reducing winter hay feeding. Additionally, cows that calve in synchrony with forage nutritive value do not require supplemental feed to maintain body condition prior to breeding. Figure 1 shows the difference in winter hay and supplemental feed usage and delivered feed costs for cows in a Kansas native range forage system with an average calving date of March 1 or April 15.

Many factors affect the sale price of calves including supply and demand, cost of gain the feedlot, and geopolitical issues, all of which the producer has very little control over. Several analyses of performance and financial records indicate that the most profitable operations are those that have low cost of production, which the produce has more control over. Even though later born calves will be lighter at the same sale date and likely even at the same age, controlling costs can improve net returns. Thus, matching cow requirements with forage nutritive value by adjusting the calving season can increase the economic sustainability of a beef operation.




Figure 1. Estimated winter hay and supplement usage, and delivered feed costs for beef cows with an average calving date of March 1 or April 15. Feed costs are calculated using $60/ton and $200/ton for hay and supplement, respectively.

Regenerative vs. Sustainable Agriculture: What is the difference?

By Phillip Lancaster

In the last 20 to 30 years, there has been a lot of discussion about sustainable agriculture. ‘Sustainable’ has been a buzzword in many industries for the last 20 years with everybody from farmers and ranchers to multi-billion-dollar corporations trying to find ways to be more sustainable. But what does the word sustainable really mean? If we break down the word, ‘sustain’ means to strengthen or support according to Oxford Dictionary. In the context of agriculture, we generally think of sustainability as the ability to support or maintain food production into the future, which suggests more efficient resource use. Agriculture has made tremendous strides in efficiency of resource use over the last 50 years.

Lately, the term regenerative agriculture has become a new buzz word, but it is really not a new concept. Robert Rodale coined the term ‘regenerative organic agriculture’ in the late 1970s as an approach that encouraged continuous innovation and improvement. Breaking down the word, regenerate means to regrow or replace what is lost. In the context of agriculture, we generally think of regenerative as replacing soil carbon/organic matter that was lost due to soil tillage or overgrazing. Again, agriculture has made tremendous strides in replacing soil carbon with adoption of no-till and cover cropping practices, and management intensive grazing in the last 30 years.

There are other aspects of the ecosystem such as plant and animal biodiversity that also fall under the idea of regenerative agriculture. Researchers are beginning to understand how grassland and rangeland management impacts plant species composition and wildlife populations, and developing novel management strategies to such as patch burning to enhance plant and animal biodiversity.

Many of the agricultural management practices that we considered sustainable are also regenerative. Whether the practice is sustainable or regenerative depends on the context of the situation in which the practice is being used. All soils have a maximum attainable soil organic carbon content based on physical characteristics (clay content, bulk density) and climate (rainfall, temperature). For example, a rancher whose soil has reached its maximum attainable soil organic carbon and practices management intensive grazing is sustaining the level of carbon. A second rancher whose soil has not reached its maximum attainable soil organic carbon and practices management intensive grazing is regenerating the level of carbon. Thus, even though they are using the same management practice, the first rancher is practicing sustainable agriculture whereas the second rancher is practicing regenerative agriculture.

As with soil organic carbon, a maximum attainable level of other aspects of the ecosystem will be achieved with regenerative agriculture.  At this point, we will move from replacing what was lost to maintaining the new level, and from regenerative agriculture to sustainable agriculture.

The Confined Cow-Calf System: Tradeoffs Between Environmental and Economic Sustainability

With the high cost of pasture and rangeland, alternatives to grassland cow-calf production are being investigated with cows and/or calves being in confinement all or part of the production cycle. There are many management options with year-round confinement in regions where grazing grass or crop residue is not possible or desirable, short-season grassland grazing during summer and confinement during winter, or confinement during summer and crop residue/cover crop grazing during winter. Harvesting and delivering feed to the cow rather than the cow harvesting feed herself always adds cost to the production system, and thus, confinement or semi-confinement cow-calf systems have additional costs that need to be offset in some way.

One advantage of having cows in confinement is improved feed management with control over the quality and quantity of feed consumed by the cow-calf pair. By limit feeding cows a high energy, by-product diet during the confinement period, maintenance energy requirement is reduced 20 to 40% compared with a low-energy, forage diet fed ad libitum. This reduction in maintenance energy requirement decreases the total feed energy necessary to maintain the cow. Additionally, the calf has access to higher quality feed (ration vs. grass) and weaning weight is increased if the confinement period coincides with mid and late lactation. The higher quality and lower quantity of feed consumed by the cow reduced methane emissions and would likely require less land improving the sustainability of beef production.

But, as mentioned above, there are additional costs for feed, facilities and equipment, and labor; studies indicate that the net returns decrease as the length of the confinement period increases. Additionally, even though less total land would be used, the amount of land under intensive crop production would likely increase reducing ecosystem services provided by grasslands. Also, the conversion efficiency of non-human edible protein to human edible protein decreases with the use of high-energy, by-product diets because more human edible protein is used in the diet. Protein conversion efficiency is one of the most positive attributes of using ruminants for food production and should be a primary goal in designing any cattle production system.

Developing an economically and environmentally sustainable cow-calf production system will be difficult. Changing one aspect of the system to cause an improvement in one metric can easily result in moving another metric in the wrong direction. The beef cattle production system needs to be evaluated as a whole and careful analysis should be completed before making decisions.


Figure 1. Cow maintenance energy requirement (MEm, Mcal/kg.75), cow methane emissions (CH4, CO2 equivalents/kg HeP), human edible protein conversion efficiency (HePCE, %), and net returns (Returns, $/cow) for conventional pasture-based and semi-confinement (3-4 months) cow-calf production systems

Reproductive Management of Beef Cattle Herds

Bob L. Larson, DVM, PhD

There are a number of important factors that interact to impact the number of calves weaned per cow exposed for breeding. One of the important factors that is often not recognized is that the previous years’ timing of calving will have either a positive or negative effect on this year’s reproductive success. I use the term “herd momentum” to describe the impact that previous reproductive outcomes have on the current and future reproductive performanceof the herd.

Several key facts about the cattle reproduction and cow-calf production impact each year’s reproductive success. First of all, it is necessary for beef cows to calve at about the same time each year in order to appropriately match the cow production cycles with the forage production cycle. Recognizing that pregnancy lasts 283 days means that there are 82 days from the time a cow calves to the time it needs to become pregnant again to maintain a 365 day calving interval. This fact is important to remember when we understand that beef cows have a period of time after calving, called postpartum anestrus, when they do not display heat behavior necessary to initiate mating and they do not ovulate fertile eggs. It takes about 70 to 100 days from calving for 90% of cows to resume fertile cycles if they are in good body condition, but this period is longer in cows that calve in thin body condition. Because of these limitations, only cows that calve in good body condition during the first 42-52 days of calving are likely to resume fertile cycles before the start of breeding or during the first 21 days of breeding. In contrast, cows that calve later than the 52nd day of calving are not likely to resume fertile cycles until the second 21 days of the breeding season or later.

Most producers recognize that first-calf heifers take about 20 to 30 days longer to resume fertile cycles after calving than mature cows. In order to have fertile cycles by the start of the breeding season for their second pregnancy, first-calf heifers need to calve in good body condition at least 100 days ahead of breeding – which is before the mature cows start calving. 

Whether cows calve in the first, second, or third 21 days (or later) in the calving season impacts the timing of when they will resume fertile cycles and can become pregnant in the following breeding season; therefore, cow-calf herds have reproductive momentum from year to year. This momentum can be positive (most cows calve early in calving season and breed early in the following breeding season) or negative (most cows calve late in calving season and breed late in the following breeding season). Positive momentum results in cows that calve early and have increased longevity in the herd. 

Another important fact to understand about cattle reproduction is that even when a perfectly fertile cow is mated to a fertile bull, not every mating will result in successful fertilization and embryo development. In fact, we estimate that the likelihood of a fertile mating will result in pregnancy that can be detected at preg-check time is 60 to 70%.

Most commonly, this pregnancy failure occurs during the first 14 days of pregnancy and the cow will express heat and ovulate a fertile egg about 21 days after her last heat and have another 60-70% chance of conceiving and maintaining a pregnancy. Cows with three opportunities to be mated to a fertile bull (each with a 60-70% probability of a successful pregnancy) during a breeding season will have a 90-95% probability of giving birth to a calf at the end of gestation. Animals in the herd expected to have completed the postpartum anestrous period and to be having fertile estrous cycles by the 21st day of the following breeding season include: nearly all mature cows that calve in good body condition during the first 21 days of calving, many of the mature cows that calve in good body condition in the second 21 days, some of the cows that calve between 42 and 52 days into the calving season, and first-calf heifers that calve before the start of the mature cow calving season. 

Cows with only two opportunities to be mated to a fertile bull during a breeding season will have about an 84% to 91% probability of becoming pregnant and maintaining a pregnancy to the end of gestation. Cows with only two or fewer opportunities for mating would include mature cows that give birth to a calf more than 42-52 days after the start of the calving season, first-calf heifers that calve after the start of the mature cow calving season, and first calf heifers or mature cows that are thin and have a prolonged period of postpartum anestrus. 

Extending the breeding season longer than 65 days (three 21-day periods) will allow more cows to become pregnant, but cows that conceive more than 52 days after the start of breeding are very unlikely to begin fertile estrous cycles until the second or later 21 day period of the breeding season, and cows that conceive more than 82 days after the start of breeding will not calve until after the start of the following breeding season. This scenario could be described as “negative reproductive momentum”.

From a reproductive standpoint, herds should be managed so that 95% or more of the cows have resumed fertile cycles early enough to be mated during the first 21 days of the breeding season. This will result in herds that are “front-end loaded” and have “positive momentum”, in that 60% or more of the cows will calve in the first 21 days and 85% of the cows will calve in the first two 21-day periods. In order to achieve this goal, producers must focus on: developing heifers to become pregnant early in the breeding season, ensuring bull breeding soundness, aligning the calving period with optimal resource availability, managing forage and supplementation to ensure good cow body condition going into calving, and minimizing reproductive losses due to disease.

Record Keeping

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

Because cow-calf operations characteristically have high operating costs and deal with fluctuating input and sale prices, ranches typically operate within a narrow profit margin. However, there are great differences between ranches in their overall profitability as defined by the difference between prices received and operating costs. In order to maintain a profitable ranching operation, producers must continually look to improve herd efficiency through increasing the value of animals sold and/or decreasing the cost of production. The use of records is essential to identify sources of inefficient production so that management changes can be implemented, and then to track the effects of management decisions on production efficiency. In addition, the trend toward “identity preservation”, and “process verification” has led to new opportunities for those producers that can document production practices as well as growth efficiency and carcass quality after cattle leave the ranch.

Veterinarians who work with beef cattle producers often desire records to assist in the assessment of production efficiency, to help in the investigation of disease outbreaks, and as a component of Beef Quality Assurance (BQA). Different veterinarians have preferences for different types of records and record-keeping systems, but all would agree that having accurate information about the herd has many valuable uses.

Systems for gathering data for records are numerous and varied. These systems can collect data on either the whole herd or on individual animals. The simplest form of record gathering is head counts for the purpose of keeping accurate inventories. The next level of record gathering is whole herd data that includes percent calf crop, percent pregnant, average sale (weaning) weights, etc. and this type of record gathering is adequate to get a picture of overall herd performance. The next level of record keeping involves individual animal performance records which provide the best information for identifying problems and possible solutions, however, this type of system requires a greater commitment in time and expense.

From a record-keeping standpoint, the needs of cow-calf ranches differ from other livestock operations such as dairies, feedlots, and swine or poultry operations in that cow-calf ranches only collect usable information at a few specific times of the year such as at preg-check, weaning, pasture turn-out, or at times that specific ranches handle their cattle. This is in contrast to other livestock production systems that hand-deliver feed on a daily basis, measure production on a daily (dairy) or at least weekly or monthly (swine or poultry) basis due to frequent marketing, and tend to have more animals so that treatment for disease is a frequent activity of herd management. Because of these differences, the relatively low amount and frequency of data collection in cow-calf herds allows ranchers to have very effective record keeping systems that are simpler than systems needed by other livestock production systems. In fact, a lot of important information can be captured on the ear tag or freeze brand (year of birth, sire breed, calving order – i.e. calved early or late in calving season) and paper or relatively simple computer programs can be used to keep and organize ranch production and health records. It is important to gather all the information that you will need to make decisions, but it is not necessary to set up record-keeping systems that collect information that is not used.

One area of record keeping that is valuable for cow-calf ranches and their veterinarians is information to measure reproductive efficiency. The information that is needed to identify opportunities for enhanced reproductive efficiency and to help diagnose reproductive inefficiency includes: accurate estimates of when cows become pregnant, cow characteristics such as age and breed, and breeding group information such as which bulls were in the breeding pasture, characteristics of the breeding bulls such as age and breed, the length of the breeding season, and a record of any events such as bull injury that occurred during the breeding season. Veterinarians can use this information to create graphs that show how many cows become pregnant each 21-day period of the breeding season, and can determine if specific ages, breeds, or breeding groups are not as reproductively efficient as the rest of the herd.

When veterinarians investigate disease outbreaks, information about which cattle got sick or died (age of cattle affected), what behavior the rancher saw that caused concern, the date an animal was first identified as sick or died, and which pasture or lot the sick animals were housed in prior to being identified can all be used to look for patterns in age, location, dam age, or other characteristics that help identify the events that led up to the disease problem. Any information about individual sick cattle or outbreaks of disease should be kept for several years so that if a similar problem reoccurs, accurate information is available.

Beef Quality Assurance (BQA) involves several aspects of cattle management that directly affect the quality of the beef products sold to consumers as well as the health and welfare of the herd. Accurate documentation of all events that occur to an animal from the time of birth, through all of the production phases and on into the slaughter house is becoming the expected level of record-keeping.  Whenever a vaccine, dewormer, fly control, antibiotic or other product is administered to cattle, you should record the exact name of the product, the serial number of the product you purchased, the dose that was administered, and how the cattle were treated (i.e. by mouth, in the muscle, under the skin, etc.).

If you are considering a change in your record keeping system, it is important to develop a system that collects all the information that you need to make the management decisions that you are targeting; but in the simplest manner than accomplishes your goal. The output of any record keeping system should allow you to easily and accurately see the overall productivity of your herd as well as to use individual performance data to make management changes that improve overall efficiency.

Hy-Plains Feedyard with Paula

Written by: Patti Dollarhide

Paula Ghazarian

“Paula, do you want to go on a road trip?”

“Sure, where to?  We made great memories when we traveled to the nutrition conference in Miami on the beach a few years back.  When and where?”

“June 20, 2019 at Hy-Plains Education & Research Center, Montezuma, KS.  Be sure to wear close-toed shoes.”

And that is all it took to get my friend Paula Ghazarian, RN, leader of the Infection Control oversight team at one of the largest hospitals in Kansas for many years, to attend the “Appropriate Antimicrobial & Use & Stewardship” conference several hundred miles away.  She is a life-long learner who pursues learning no matter what the time or setting.  Paula was raised in West Virginia and has stories about raccoons, squirrels and prized coon dogs that make you laugh so hard your stomach hurts, but we soon found that cattle chat was a foreign language to her.  The cattle talk took us to other health-related topics.  I could feel some common ground as she shared her frustration with parents who choose not to vaccinate their children, resulting in outbreaks of vaccine-preventable diseases.  This easily translates to the cattle business as our customers want us to stop using antibiotics to treat food animals.

We arrived at the Hy-Plains feedlot a little early, and Tom Jones took time to give Paula a tour of the cattle processing area.  Her morning started off with amazement.  “I had no idea it would be so calm, quiet and clean.  I was expecting chaos and very bad odor.”

Paula asked a few questions that were easy to answer, as well as some that don’t really have answers.  She was disappointed that a retailer she held in high esteem due to their stand against antibiotics in chickens has created a trade-off that includes a negative effect on animal welfare.  Increasing animal mortality is not the outcome she wants.

As the day went on, speakers discussed opportunities in our business to reduce stressors that drive how we currently use medically important antibiotics   Modern beef production is a highly specialized business in which technology has allowed farmers to produce more food for a growing world and still stay in business – a cattleman’s ultimate definition of sustainability.

Two different times during the day, questions came from the agriculture audience wondering what the human medical community is doing to address appropriate use and stewardship.   We know, and they know, that there are opportunities.  Paula shared multiple examples on our return trip of how practices and procedures have changed, such as simple oversight in the ICU to remove Foley catheters after three days which had an immediate impact on infection reduction.   She also shared case studies that her specialized infectious disease team worked with that would break your heart.

One Health recognizes that the health of people is connected to the health of animals and the environment.  Research and industry collaboration are essential.  I was proud to have my friend see and hear the efforts that are going on in the agriculture community to make change so she will trust our food supply and want to continue to eat beef

My hope for future meetings is to include more human health professionals in our discussions.  Let’s hear what initiatives they are working on and address antimicrobial use together.

Thru the eye of an infection control nurse not familiar with USA Beef production:

  1. How do the animals get out of this chute?  How do you get them back to the pen?
  2. Why do you track “days on feet”?  Aren’t they always on their feet? 
  3. What are “check off dollars”?
  4. I have never heard of ionophores in human medicine.  What are they? 
  5. There is a lot to know about.
  6. How to the producers at the farmer’s market fit into this model?
  7. There are trade-offs. 
  8. I never thought about how we grind different animals together to make hamburgers.
  9. Antibiotic resistance is everyone’s problem.  We have a lot of examples of changes we have made in human medicine, as well as a lot of challenges this group might be interested in.

Using the Pregnancy Analytics Mobile App: Bull problems and BSEs

The Beef Cattle Institute’s Dr. Bob Larson brings you a series of “cases” employing the use of the Pregnancy Analytics mobile app. Each case will explore a unique herd and examine its reproductive efficiency, strengths, challenges and areas of improvement. The reports (linked below) will lead you through using the Pregnancy Analytics app to utilize the data and practice using it on an actual problem herd.

The case: Bull problems and BSEs

A herd of 209 commercial red-composite cows was palpated on October 7. The herd is split into three breeding pastures with bulls being turned out on June 10 and removed on August 15. The calves were being weaned on the ranch (i.e. left in their current pastures) and the cows were being trucked to a new pasture so the owner started dropping off cows at your clinic very early in the morning to be preg-checked, dewormed, and vaccinated before being taken to fall grazing on corn stalks. During the breeding season: 62 were in the “West Pasture” with two bulls, 81 were in the “North Pasture” with three bulls, and 66 were in the “Windmill Pasture” with two bulls. About 60% of the first-calf heifers were in the West Pasture –– with the rest split between the other two pastures.

Findings

Seventy-six cows were open (64% were pregnant) and only 8% of the cows were classified as being “thin” (BCS <5).

The first analysis of the preg-check data was to look at the percent of the herd that became pregnant each 21-day period of the breeding season and we find that 44.5% of the herd became pregnant in the first 21-days (pregnancies would have been 98 to 119 days), 13.9% in the second 21-day period (77-97 days), and 5.3% in the third 21-day period (56-76 days). The goal for this herd (and most herds) is to have at least 60% of the cows becoming pregnant in the first 21 days of breeding.

Another way to evaluate preg-check data is to determine the percent of the available (non-pregnant) cattle that become pregnant each 21-day period. Recognize that as the breeding season goes along, once cattle become pregnant, they are no longer available to get pregnant again, so the percent of the herd that becomes pregnant each 21 days is not the same as the percent of available cattle that become pregnant each 21 days. To display this measure of reproductive success using the Pregnancy Analytics App – select “% Preg Success”. Based on expected pregnancy success when both cow and bull fertility is optimum, the “% Preg Success” goal should be between 60%-70% for every 21-day period of the breeding season.

Looking at the percentage of open cows that became pregnant each 21-day period, we find that either cow or bull fertility (or both) was lower than desired at the start of the breeding season (44.5% settling in first 21 days) and pregnancy success did not improve and in fact got worse as the breeding season progressed (25% in the second 21 days and 12.6% in the third 21 days).

In this herd, the poor over-all percentage pregnant clearly indicates a problem and the percent pregnant by 21-day interval provides information that the poor reproductive performance continued for the entire breeding season. To begin to evaluate the herd further, the Pregnancy Analytics App provides a way to easily divide the herd into pertinent sub-groups – and when the pregnancy success by 21-days is evaluated by age group, we find that both the first-calf heifers and the mature cows had too many open cows. (1st-calf heifers are defined as those cows suckling their first calf and being bred for their second pregnancy).

More information can be found by displaying the % Preg Success and while neither the 1st-calf heifers nor the cows reached the expected reproductive performance of 60-70% of open cows becoming pregnant in a 21-day period –– the 1st calf heifers tended to perform better than cows and the performance declined over the breeding season.

The preg-check data can also be evaluated by comparing the breed-up differences between body condition score categories. We know that only 8% of the herd was classified as “thin” at the time of preg-check, so we may be justified to ignore any assessment of the association between BCS and pregnancy distribution in this herd; but to be complete, I looked at BCS and found that cows classified as being in moderate body condition performed as poorly as cows classified as being thin.

So far, the information I have looked at raises the possibility of either Trichomoniasis or bull problems being the most likely rule-outs – with cow infertility due to nutritional or late-calving being less likely because the magnitude of open cows is more compatible with bull problems or Trich and the fact that fertility does not improve as the cows have more time post-partum to resume fertile cycles as the breeding season progresses.

The most revealing information about this herd is obtained by looking at the effect of breeding pasture on reproductive performance (both the pregnancy distribution and % Preg Success).

I interpret this information as evidence that the primary problem for this herd is in the Windmill pasture. The other two pastures (West and North) perform very well early in the breeding season – indicating that the cows must have had time post-partum and adequate nutrition pre- and post-partum to resume fertile cycles by the 21st day of the breeding season. Nearly all the open cows were in the Windmill pasture and fertility was very poor throughout the breeding season. The magnitude of the infertility is worse than I would expect for Trichomoniasis and definitely worse than I would expect with a cow problem (in addition, excellent cow performance in the other pastures pretty much rules out a cow problem). The poor reproductive performance in the Windmill pasture must be due to a bull problem.

Conclusion

The primary problem in this herd is in the Windmill pasture and almost has to be due to a bull problem even though the rancher reports that all the bulls were between three and five years of age and had been successful breeders in previous years. I would recommend a BSE on both bulls from this pasture, but if one or both bulls pass the BSE, my diagnosis would not change (finding a musculoskeletal or semen problem in one or both bulls would confirm the diagnosis).

To prevent this problem in the future, I would strongly recommend a BSE for all bulls before the start of breeding and frequent assessment of bull musculoskeletal health and amount of estrus activity throughout the breeding season.

Download the report here.

Vet Call: Anaplasmosis

By Dr. Bob Larson, DVM, professor of production medicine
Reprinted with permission from the Angus Journal.

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 yellow discoloration of the mucus membranes, fever, depression, dehydration and rapid or difficult breathing. 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 transferred between 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 a blood transfusion to replace red blood cells and/or with an injectable tetracycline antibiotic to kill the organism. In addition, healthy animals should be moved away from the affected cattle to reduce the risk of the organism being transferred to the rest of the herd by ticks or biting insects, and low levels of tetracycline can be fed in the mineral mix or supplement to provide additional protection to the herd.

For carrier cattle that don’t appear sick but that are infected with the anaplasma organism, your veterinarian can plan a treatment protocol using tetracycline antibiotics administered over several days to clear the organism. However treatment with tetracycline 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 tetracycline 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 tetracycline treatment and if a positive is found 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 low levels of chlortetracycline when the disease is most prevalent to control active infection and 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 with tetracycline 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 purposeful exposure (or 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.

Dr. Bob Larson is a professor of production medicine with the College of Veterinary Medicine at Kansas State University, Edgar E. and Elizabeth Coleman Chair of Food Animal Production Medicine, executive director of Veterinary Medical Continuing Education, and faculty member with the Beef Cattle Institute. He specializes in the integration of animal health, production efficiency and economic considerations in beef cattle production. This column is reprinted and redistributed with permission from the Angus Journal.