Dealing With Trich
FORT COLLINS, COLO. (Dec. 3, 2008) — Trichomoniasis and bovine viral diarrhea (BVD) are reproductive diseases that can both have a big impact on the profitability of a cattle herd. That’s why it is important that producers use management and biosecurity to mitigate these diseases, Bob Mortimer, associate professor of integrated livestock management at Colorado State University, told attendees of the Robert E. Taylor Memorial Symposium: Applied Reproductive Strategies in Beef Cattle Dec. 3 in Fort Collins.
“Some of these management practices are so simple,” Mortimer said in his opening remarks. Because trichomoniasis, or trich, has been a focus of his career and is of big concern in Colorado, Mortimer focused his remarks on that disease.
Trich commonly causes poor pregnancy rates, with 10%-50% open cows not uncommon. It also tends to spread out the calving season, reduce weaning weights and increase herd health costs. Mortimer emphasized that to combat this costly disease it is necessary to understand what causes it and then design a plan to keep it out of your operation.
What is Trich?
Tritrichomonas foetus is a single-celled protozoan that is transmitted sexually. In bulls, the organism localizes in the crypts, or microscopic folds within the skin surface of the penis and sheath, Mortimer explained. Because these crypts become deeper as the bull ages, there is an association between age and infection. Mature bulls are more apt to become infected and stay infected. And, once a bull is infected with trichomoniasis, he is infected for life.
The bottom line in managing and treating trich is for producers to be knowledgeable enough to put a biosecurity program together to protect themselves, CSU's Bob Mortimer said.
Infection of the cow can take place at breeding, but Mortimer noted that not every female will become infected when bred. If the protozoa is transmitted to the female, it will attach to the cells lining the vagina. The protozoa form colonies, which spread to the uterus and oviducts, resulting in an inflammatory response. This may cause the cow to abort her calf and rebreed, or cows may carry the infection for several months and then are able to mount an immune response and clear themselves of infection, but they are then susceptible again to the infection.
Because the bull is a chronic (lifetime) carrier, and cows can clear the organism following infection, herd diagnosis usually is made by testing bulls, Mortimer explained.
Diagnostic testing of samples from the sheath are necessary for diagnosis. It is recommended that bulls have at minimum two weeks of sexual rest before undergoing testing. And, in order to make a definitive diagnosis, it is recommended that bulls be sampled by a veterinarian once a week for three weeks in a row, Mortimer said.
Mortimer said the bottom line in managing and treating trich is that producers need to be knowledgeable enough to put a biosecurity program together to protect themselves.
Because there is no treatment approved for trich, bulls that test positive should be sent to slaughter. “This doesn’t mean you sell him to somebody else. That is how the problem is spread,” Mortimer said.
Additionally, he advised working with neighbors to ensure that all herds with fenceline contact have the same focus on managing trich. “This is a disease of neighborhoods. If you can’t get your neighbors involved, you’re never going to get it out of the area,” he said.
If neighboring pastures are leased out for grazing, he suggested working with the local cattlemen’s group to write the landowner or leasee a letter asking that screening for trich (and other transmittable herd diseases) be part of the leasing agreement. For grazing associations with cattle from multiple herds, Mortimer also emphasized that it is important that all bulls be screened.
Likewise, leased bulls are a concern because they often are in multiple herds. “If you are going to lease a bull, require at least three negative tests," Mortimer said. "Keep in mind that takes 30 days.”
He added, “This is an easy disease to handle, but it’s got time constraints for the testing.”
Mortimer said vaccination is available for cows, but it is not effective for bulls. Additionally, he said it does not prevent infection in cows, but it may decrease the severity of the disease.
Additional management tips from Mortimer include:
- If possible, incoming cows should be virgin heifers from a reputable source.
- Purchase only virgin bulls or bulls tested negative via three weekly tests.
- Using AI and synchronization programs can also decrease the need for bulls and the risk of exposure to Trich. Be certain the semen comes from a reputable source.
— by Kindra Gordon
Editor’s Note: This article is available as a news release to redistribute per an agreement between the symposium hosts and Angus Productions Inc. Click here to submit a request for a high-resolution photo of the speaker. For additional information visit the newsroom of www.appliedreprostrategies.com.
The Robert E. Taylor Memorial Symposium is conducted by Colorado State University every other year to provide current, research-based information for improving profitability in the beef cattle industry. The ARSBC program was developed by the Beef Cattle Reproduction Task Force to improve understanding and application of reproductive technologies, including AI, estrus synchronization and factors affecting male fertility. In 2008, CSU and the Task Force collaborated to provide the Dec. 2-3 symposium in Fort Collins. To listen to this presentation, view the accompanying PowerPoint or view other presentations from the symposium, visit the newsroom at www.appliedreprostrategies.com.