Although familiar infectious cattle venereal diseases like leptospirosis and vibriosis remain a thorn in the side of producers, another disease has been getting a lot of recent attention.
Cattle trichomoniasis – commonly known as “trich” – is spread by a protozoan organism, Trichomonas foetus. It lives in the reproductive tract of the cow, and in the sheath of the bull’s penis; cows can rid themselves of the disease in three months, but bulls are often infected permanently, and can shed the organism indefinitely while showing no outward signs of the disease.
The economic losses to the U.S. beef industry from reduced conception rates, lowered weaning weights and increased culling due to trich exceed $100 million annually; the disease has long been familiar to Western ranchers. University of Missouri Extension livestock specialist Gary Naylor said, “we’re seeing more of it in the state of Missouri.” Missouri now requires bulls imported from other states to be tested for trich if they are not virgins, more than 24 months old, or destined for slaughter.
The test has to be conducted by a veterinarian and sent to a lab. There are also vaccines; both tests and vaccines cost a few dollars per head. The vaccines are for females; if you’ve got a bull with trich, get rid of it. Naylor offered this case study of a producer who had a set of bulls: “A neighbor needed to use a bull, and he let the neighbor use one of the bulls, and then when we came back to his herd he had this problem. They tested for it, and he tested positive; then he spread it throughout the whole herd. You know, when you’ve got several bulls and lots of females, it gets spread pretty easily. I’ve heard of situations where they only run 30 to 40 percent calf crop where normally they would be running 80 to 85 percent.”
Limiting new bulls to your herd to virgin animals is the only way to be assured that they’re trich-free. Naylor said, “If you buy a bull and he’s been used in another herd, then probably the best thing to do would be to have him tested for this.”
There are also inoculants against the bacterial organisms that cause leptospirosis and vibriosis; Naylor said an annual vaccination program can easily prevent those diseases, but not all ranchers vaccinate. “When you vaccinate your own herd, you certainly hope that the neighbor does this also,” he said. “When you’ve got cattle across fences from each other, eventually they get together.” In addition, transmission of lepto doesn’t require sexual contact; it can be spread through urine, and Naylor warned, contaminated water supplies can lead to infection.
There are other reproductive diseases, of course, including brucellosis; Missouri, in 2003, became one of the last states to earn Bangs “Class Free” status, but the costly disorder still periodically rears its head in herds across the country. Naylor advised, Good practices – not loaning your bull; when you buy bulls, buy virgin bulls; and try to keep your herd closed. The best way to go about that is to raise your own replacements; I know some folks just don’t like to do that, but that would be the safest way to prevent those diseases.”
