Poor udders result in poor calves

Poor quality udders are a frustrating problem most beef producers encounter. Cows with large teats or non-producing quarters are typically culled in the fall. However, if a cow is missed she can have a negative effect on future calf performance and is more susceptible to infections, such as mastitis.
Mastitis isn’t considered a big problem in range cows. Cattle living in confined environments, especially dairy cows, are far more likely to become infected. However, a paper from Oklahoma State University (OSU) states that studies conducted in the late 1970s and early 1980s found between 11.9 and 17.3 percent of range cattle tested were infected with clinical mastitis. Another study conducted in 1986 found 37 percent clinically infected.
Flies can spread it from cow to cow and calves can spread it from one quarter to the entire bag. An infected cow’s udder is often tender, which leads to more instances of kicking calves off. These cows often have to be gathered and milked out, which is known to leave a sour taste in ranchers’ mouths.
OSU also found a correlation between mastitis and lower weaning weights. Calves nursing infected cows were between 7.3 and 12.5 percent lighter than their contemporaries. If a rancher is weaning 500-pound calves, a calf sucking an infected cow could be 36 to 62 pounds lighter based on these percentages. If several cows in the herd are infected, weaning weights could be reduced significantly.
Cows with pendulous, broken down udders are more susceptible to mastitis and sick calves because their udders encounter more bacteria as they are dragged through dirt, mud and water. Another known problem is reduced milk and colostrum intake by calves with “big bagged” mothers. Calves often have trouble getting on quarters with large teats and in some instances ranchers have to milk cows just out so the calf can suck.
The OSU article found that similar to cows infected with Mastitis, those with one or two dry quarters weaned calves 50 to 60 pounds lighter than the herd average. Mastitis is one known cause of dry quarters in cattle. But, if a calf is unable to suck a quarter due to an enlarged teat his performance will also be compromised.
Dr. Rick Rasby of the University of Nebraska, Lincoln states that selecting against poor teats and udders can increase calf performance and reduce calf sickness in addition to increasing cow longevity and reducing labor inputs. Conformation of udders and teats is considered low to moderately heritable. Selecting AI sires whose daughters possess high quality udders and only keeping replacements from cows with good udders can reduce the problem in a herd.
If a rancher keeps data on cows, adding udder and teat quality can help make management decisions. If a cow has a big bag or teats in the spring after calving, write her number down. Doing so ensures she won’t be missed in the fall after she’s dried up and may not be as noticeable.
Benefits of eliminating bad uddered cows include a heavier, more uniform calf crop and the reduced stress of getting a cow in, milking her, and getting to know her personally. Keeping data on cow udder quality can reduce future females who exhibit the problem.
Article compiled from OSU and UNL information. Heather Hamilton is editor of the Wyoming Livestock Roundup and can be reached at heather@wylr.net