Last week in my article about artificial insemination (AI), I made a comment about one of the advantages of (AI) was that it can reduce the danger of spreading infectious genital diseases from bull to cow during a natural service. One of these diseases prevalent in our area is Trichomoniasis commonly referred to as "trich," Trichomoniasis infection of cattle is a devastating disease for cattle producers. When diagnosed in a herd, it causes economic loss and emotional pain. There is no treatment for Trichomoniasis infection. Therefore, emphasis must be placed on prevention. The foundation of building a prevention program for your herd is testing all the bulls that will have exposure to your cows.
In today's world of ever increasing input costs, producers are looking for ways to cut expenses. The following information will not only encourage beef producers to continue testing for Trichomoniasis, but will also encourage those who do not test to include it in their herd health management program.
Trichomoniasis is caused by a protozoan organism, (Tritrichomonas foetus). The primary mode of transmission is from sexual contact during the act of a bull breeding a cow. When a cow becomes infected, the following can happen.
• Trichomonas foetus infection can cause the cow to be infertile and she continues to cycle until she builds up immunity. (Immunity is usually short-lived and the cow can become re-infected.)
• The cow can become pregnant but then early in the pregnancy; she aborts and comes back into heat.
• The cow can carry the fetus to full term, can remain infected, and shed the infective Trichomoniasis protozoan after calving.
Most often, the first clinical sign of trichomoniasis in a herd is an increased percentage of open cows or "late" cows at the fall pregnancy check. If fall pregnancy checking is not done, clinical signs in the herd are reduced calving rate and a calf crop that is strung out over three to six months.
Bulls will show no signs of the disease but can shed the organism indefinitely, and is the main source of transmission for the herd. Trich typically gets introduced into a herd by the introduction of one infected animal, an infected bull. To diagnose the disease, a preputial fluid sample is taken from the bull. The preputial sample is sent to a veterinary diagnostic lab where a culture or a PCR test is performed. Once a diagnosis of trichomoniasis is made in a herd, control and prevention of future infections involves culling the infected bulls and retesting any negative bulls until three negative tests are obtained.
In 2008, a survey was sent to Colorado veterinarians in bovine practice to gain insight on Trichomoniasis in cattle herds and to determine the median veterinary costs of herd testing bulls for Trichomoniasis.
The results revealed that a producer that has a 100-cow herd uses one bull per 20 cows, and lives 75 miles from a veterinary clinic will incur $2.93 per cow to test all of the herd bulls for Trich. It will only cost another $1.50 per cow to perform a Breeding Soundness Exam on the herd bulls to find any bulls that are "infertile" or "sub-fertile." The total cost is $4.43 per cow for Trich testing and Breeding Sound Exams. This cost per cow is a bargain considering the lost opportunity of having a pregnant cow ready to calve within a pre-determined calving season. In short, performing breeding soundness exams and Trich testing before the breeding season is inexpensive insurance against a disease outbreak and/or a breeding season disaster due to low calving rates.
Is there a vaccine? Yes. Fort Dodge currently markets a vaccine made from killed whole cells of Tritrichomonis foetus. Tests of this vaccine have shown that experimentally infected, vaccinated females "clear" a vaginal infection in a matter of a few weeks, whereas control (unvaccinated) females can remain infected for months. As of this date, no efficacy for bulls has been shown, i.e. the vaccine has not been shown to protect bulls from becoming infected. Also, vaccination of the bulls with the "Trich" vaccine will not eliminate the organism from the bulls. Vaccination requires two injections, typically administered 2 to 4 weeks apart. Consult with your veterinarian when starting a trichomoniasis vaccination program for your herd.
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