Trich Testing is NO Bull

Although this bull does not have trich, all bulls in a herd should be tested to be certain since there are no outward signs to show a bull is trich positive. (Photo by Jelly Cocanougher)

By Jessica Crabtree & Dr. Jered Harlan 


What is trichomoniasis-

Better known as “trich,” it is a venereal disease of cattle that causes reduced calf crops, decreased weaning weights due to open cows and a prolonged breeding season. Trich is caused by Tritrichomonas foetus which is a microscopic flagellated protozoan parasite that is confined to the reproductive tract in an infected animal, in this case bulls. It can be transmitted from the infected bulls to heifers or cows at the time of breeding. Trich ultimately results in cows losing pregnancies, causing a disrupted breeding season and low yield in calf crop. Bulls with trich carry the protozoa in their preputial sheath and penis. The cow, in contrast, harbors the organism in the vagina and uterus.

What does trich look like? What symptoms can I look for?

Bulls affected by trich show no outward clinical signs of having any issues. Even more aggravating, the parasite does not affect a bull’s semen quality nor sexual behavior when breeding. Bulls will breed cows as normal, transmitting the infection during breeding. Therefore, the only way to prevent entry of trich into a herd is to test each bull prior to using.

How will my cows be affected?       

Trich presents itself in two different forms. The first is cows affected may become pregnant, undergo embryonic death and cycle regularly without showing any signs. It is only realized at pregnancy diagnosis when higher numbers of open cows are presented. The second way a cow can be affected is she cycles regularly and builds up immunity after three days.

To read more pick up a copy of the January 2018 NTFR issue. To subscribe call 940-872-5922.