Several generations of Oklahoma cattlemen grew up with the reality of required Bangs testing of their breeding stock at change of ownership. In 2009, however, required brucellosis testing at sale barns ended.

But, Oklahoma cattlemen are now faced with an emerging reproductive disease in cattle that may once again require testing of breeding stock at change of ownership – trichomoniasis (commonly called trich), says Dave Sparks, Oklahoma State University Extension food animal quality and health specialist.

Trich is a protozoal disease spread among cowherds by venereal contact. It shows up as various infertility problems including open cows, late calves, abortions and uterine infections. In time, infected cows often develop sufficient immunity to conceive and carry a calf to term, but the immunity is short-lived and, if exposed to an infected bull again next year, the problem repeats itself.

One bull can infect a few cows, which infect several bulls, which infect many more cows, Sparks says. If undetected, the problem is usually much worse in the second year. Bulls are carriers of the disease and most bulls, especially those over 2-3 years of age, are carriers for life. Slaughter of infected bulls is the only way to prevent the spread of the disease.

Sparks says trich isn’t a new disease, but it’s becoming much more common, thanks to easier movement of bulls, leasing bulls, and purchasing non-virgin bulls.

“Oklahoma currently has regulations for bulls being brought in from out of state,” Sparks says. “The legislature is also considering new regulations that would require testing whenever Oklahoma bulls change hands.”

Sparks says the extent of trich infection in Oklahoma isn’t known, but when Texas started mandatory testing of bulls at change of ownership, it found about a 3% rate of positive tests. Most authorities expect the numbers to be similar in Oklahoma.

“This is a disease we will be hearing much more about in the months to come, so take advantage of opportunities to educate yourself,” he adds. “If your herd’s number comes up in the disease lottery, it will be a very big problem for you.”

Editor’s note: For more on trichomoniasis, see “Tracking Trich” at Or, read what the Noble Foundation has to say on the topic at
-- OSU Cow-Calf Corner