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Of Udder Importance By KATRINA WATERS They are usually associated with dairy herds, but udder problems, including mastitis, are costly for beef cattle producers, too. At a 2008 TSCRA member gathering in Cleburne, Dr. Glenn Rogers spoke briefly on the topic, one he considers important and underestimated among beef cattle producers, especially outside of seedstock operations. Rogers, a managing veterinarian for Pfizer Animal Health's beef veterinary operations, says there are a number of pathogens involved in mastitis, an inflammation of the mammary gland. The disease's effects can range in severity from poor function in individual teats, to the entire udder, all the way up to death (although death from mastitis is fairly rare, he adds). Mastitis simply refers to an inflammation of the mammary gland and can decrease milk quality. While milk quantity and quality are top concerns among dairy cattlemen, it may be a little farther down the list for beef producers. But, Rogers says, they should not be overlooked. "Obviously milk production is very important for pre-weaning weight gains in calves," he explains. "If they don't have adequate milk production, they are not going to reach their full genetic potential for weaning weight." Mastitis and other udder defects may affect the quality and/or quantity of colostrum that a cow produces, directly reducing passive transfer of maternal antibodies when a calf nurses shortly after birth, Rogers says. He adds that a history of mastitis has been shown through research to be the No.1 risk factor for inadequate passive transfer. "Heifers or cows with mastitis are very likely to result in calves with inadequate passive transfer, and that can lead to lifetime health problems," Rogers says. Signs In dairy cows, mastitis is easier to diagnose but in beef cattle, where milk is not being collected and evaluated daily, it gets a little more difficult to diagnose. Rogers says studies have been conducted where milk is tested from beef cows, and they have shown a much higher incidence of mastitis than some would expect. The results range anywhere from 10 to 50 percent of cows with at least one-quarter of the udder infected. Of course, the more quarters infected, Rogers says, the more likely it is to have a more severe negative impact on weaning weight. Sometimes there are signs and symptoms, though. "It's going to be pretty obvious when you have a severe infection, whether caused by direct trauma or just a severely infected teat," Rogers says. "It could be a red, swollen and painful udder, progressing to where the udder is dark from lack of blood supply in the later stages." More often, though, it goes undetected and if noticed later, may be seen as an atrophied, non-functional quarter. Causes Rogers says trauma to the teat opening is one of the leading causes of beef mastitis. Any time there is trauma, there is a much greater likelihood of introduction of pathogens. He says trauma is a big factor in Texas, where there are cacti and rattlesnakes and some pretty harsh environments to contend with. But introduction of pathogens usually occurs from more subtle means. Poorly managed calving areas can also lead to mastitis, Rogers says. "We tend to put heifers up in small areas so we can keep an eye on them better, but if those areas become muddy, that can cause udders to have more exposure to unsanitary conditions, resulting in mastitis. Providing clean pastures with adequate drainage during calving not only aids in preventing calf diarrhea, but helps with udder health as well," he adds. Genetics also play a role. "We know that udder conformation is moderately heritable, so we can make a difference with genetic selection," Rogers says. While it's sometimes difficult or impossible to find out, he says knowing something about a bull's dam — specifically her udder confirmation — is quite valuable. As for females, he advises selecting ones that not only have good udders, but ones that come from cows without udder problems. Rogers says, "You want to select females that have udders where the suspensory ligament that divides the udder is well-attached and where the teats are perpendicular to the ground and straight up and down. You want teat placement just as uniform as possible." Selecting females with pigment to prevent sunburn on the teat is a good practice, since a sunburned teat is more prone to infection. Horn flies also can introduce and spread infection — just another reason to stay on top of fly control, Rogers says. Culling Although mastitis can be treated on an individual cow basis, it's often impractical for the commercial beef cattle producer. "It can be treated with systemic antibiotics or directly with infusions into the teat — just like we do with dairy cattle," Rogers says, adding that there are many products on the market. One treatment he cautions against is inserting tubes into the teat for drainage. "That really needs to be done carefully because we can actually make it worse by introducing more infection," he explains. "I generally don't like to see people insert objects into the teat unless it is absolutely necessary." He adds that, in many instances, treatment of severe mastitis or other udder conditions is not as good an option as culling. "Especially with labor issues like they are, it's — even in a small herd — just so difficult to manage the situation. The best thing is to try to avoid having those cows in the herd to begin with," Rogers says. It's important to remember that the culling decision based on udder health has implications not only for weaning performance, but also for overall calf health performance from the potential negative effects on colostrum, Rogers adds. He says, in his experience, balloon-type teats tend to get bigger every year. Add that to cows losing their attachment due to the natural aging process, leading to a greater likelihood of teat injury, and it becomes more of a management headache every year, Rogers says. "Udder condition should be a major part of culling decisions. Not just whether or not she's bred or her teeth condition, but also include her udder in the evaluation," he says. Rogers says there is a tendency to evaluate a cow and decide her one or two good teats will be enough to raise at least one more calf. While she often can, it's likely going to be a smaller calf than one from a cow with good teat and udder conformation. He says it doesn't matter whether you just observe them in the pasture and write down their numbers so you'll have a note when they enter the chute or look at them as they come through the chute for preg-testing, as long as it gets done. "I guess the hard thing is just doing it," Rogers says. "It requires a commitment and will take a little more time to do that, but they're already in the chute and that's something that is not that hard to look at and make notes about and do some culling there." He reiterates, "I think, absolutely, the best advice for ranchers is to rigorously cull those cows that have developed udder problems or that have poor udder conformation." Udder Suspension and Teat Size Scores
"Of Udder Importance" is from the November 2009 issue of The Cattleman magazine.
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