Author: ksubci

Tall fescue is a commonly grown forage for cattle, particularly in the southeastern and lower midwest states, as well as the Pacific northwest. This grass originally came from Europe and was discovered growing in a few isolated stands in the U.S. in the early 1930’s. It was recognized as being easy to establish with a long growing season, resistant to drought and insects, and able to grow on many types of soil. However, it was soon discovered that cattle performance was negatively affected by the grass. 

Today, we know that a high percentage of tall fescue pastures are infected with a fungus that grows inside the plant (so it is not visible to the eye) and the fungus produces a number of chemicals that provide both the positive and negative attributes of the grass. Not all fescue pastures are infected with endophyte fungus, and the percentage of plants in a given pasture that are infected will vary from one pasture to another. Generally speaking, the greater the percentage of plants infested with the fungus in a pasture, the greater the negative effects of fescue toxicosis. Although the fungus is found throughout the tall fescue plant, it is found in the highest concentration in the seed head and stems with lesser concentrations in the leaves. The fungus can be spread to un-infected pastures if infected seeds blow or are transported to bare ground where it can become established. 

Cattle grazing heavily infected stands will consume less grass, gain less weight, and have lower pregnancy rates than cattle grazing other types of forage. Cattle with fescue toxicosis syndrome are often recognized by having a rough, long haircoat and being thin. In addition, severely affected cattle will have high body temperature, and they will attempt to cool themselves by standing in water and seeking shade. Blood flow to the feet, tail switch, and ears is reduced, and in cold weather, affected cattle can slough the ends of their tails and the tips of their ears and in some cases, even the hooves can slough. 

Cattlemen with infected tall fescue pastures have a number of options. In many situations, because of fescue’s positive properties, they may choose to live with it and work to reduce the negative effects by inter-seeding legumes into the pasture to dilute the intake of fescue. In addition, if other types of forage are available, cattle can be moved off of infected pastures during the summer months when the effects are most severe. If fescue is grazed heavily so that the plants are kept short, less endophyte fungus will be present in each bite of grass. Grain supplementation also acts to dilute the amount of endophyte consumed. Cows fed grain along with highly infected fescue hay had reduced winter weight loss and improved pregnancy rates compared to cows fed infected hay alone.

Some producers may decide to invest the resources necessary to avoid the endophyte completely by replanting infected stands of tall fescue with non-infected varieties of fescue or other grasses. There are endophyte-free as well as novel-endophyte varieties of tall fescue that can be used to replace the endophyte infested stand. The novel-endophyte varieties are infected with strains of fungus that provide some of the beneficial effects with few of the detrimental effects. 

Attempts to reduce the effects of the endophyte fungus through feed additives or treatments applied to the cattle have not consistently shown benefits. However, it is recommended that cattle grazing infected fescue not be additionally stressed by heavy parasite loads, mineral deficiencies, or other disease. The best approach to managing fescue so that the negative effects of the endophyte are minimized will depend on your local conditions. By working closely with area extension and agronomy specialists, you can develop a plan for coping with this problem.

Although mastitis (infection of the udder) is often considered a dairy cow problem rather than a beef cow problem, the disease does affect many beef herds. Most cases of mastitis only involve one quarter (one teat) of a cow’s udder and the other three quarters remain normal. Even though most cases of mastitis do not result in the complete loss of milk production, calves from affected cows have lighter weaning weights than if their dam had a normal udder. Occasionally, mastitis causes severe illness in the cow, but in most situations, the cow is not greatly affected other than having reduced milk production. Mastitis can occur at any stage of lactation or even when the cow is dry, but most commonly becomes a problem early in lactation shortly after a cow calves.  

Most cases of mastitis are caused by germs that are very common in the environment and on a cow’s skin. Occasionally, mastitis is caused by injury to the udder.  Lactating cows are by far the most commonly affected, but heifers and even bulls or steers can have infected udders. Severe cases of mastitis, when the udder becomes reddened, swollen, and hot to the touch and the cow shows signs of illness such as being off-feed and inactive, will result in severe weight loss in the calf and cow and occasionally the death of either the cow or calf. Often, a beef producer or veterinarian will not notice a cow with mastitis because beef cattle are not typically observed daily from a short distance and many cases do not result in visible swelling or other signs of udder infection. In situations when cases of mastitis are not detected, the cow is likely to remain infected throughout the lactation and possibly for the rest of her life.  

If mastitis is diagnosed, cows can be treated with special formulations of antibiotics that can be infused into the udder itself through the end of the teat. The veterinarian may also choose to treat cows with mastitis with antibiotics injected under the skin of the neck that then travel through the blood stream to the udder. Many cases of mastitis respond well to treatment, but some quarters never return to full milk production. If a cow with mastitis is severely ill, the veterinarian may recommend aggressive therapy with frequent milking out of the affected quarter, the use of anti-inflammatory drugs, and antibiotic therapy.  

Because beef cows are not handled frequently, the most common time to check cows for mastitis is when they are gathered for purposes of vaccination, fly control, or breeding early in lactation, or at the end of lactation when the cows are checked for pregnancy status and/or the calves are weaned. Some herds routinely check udders and treat any affected cows at the time the calves are weaned.  

Although it is probably not possible to prevent all cases of mastitis, heavy fly populations, calving in a drylot, and poor teat and udder confirmation are linked with situations with multiple cows being affected in the same herd. Older cows, particularly those with larger, low-slung udders and large teats are considered to be at greater risk for mastitis. Therefore, prevention focuses on calving cows on clean pasture and avoiding calving in wet or muddy environments, culling potential replacement heifers if their dam has poor udder or teat confirmation, and controlling flies by focusing on sanitation and appropriate use of insecticides.