Trichomoniasis: Regulation and Importance
STILLWATER, Okla. (Oct. 9, 2014) — When trichomoniasis gets in the breeding herd, a cow-calf producer could be headed for a wreck. That was the warning shared by Oklahoma State Veterinarian Rod Hall as he addressed the Applied Reproductive Strategies in Beef Cattle (ARSBC) symposium Oct. 9 in Stillwater, Okla. Hall said small herds that aren’t managed really well often suffer most, because producers may not recognize the problem. In such cases, trichomoniasis represents a risk of significant and prolonged economic loss.
Hall explained that trichomoniasis is a sexually transmitted disease caused by a protozoan organism that lives in tiny skin crevices of an infected bull’s penis and sheath. Infected bulls remain infected for life, but show no signs of disease.
Typically, added Hall, 85% of exposed cows and heifers become infected with the ‘trich’ organism, according to Rod Hall.
Typically, added Hall, 85% of exposed cows and heifers become infected with the ‘trich’ organism. Infected females are capable of becoming pregnant, but usually abort the fetus after one to four months. They remain infected for two to four heat cycles. After a brief subsequent period of immunity, females become susceptible to reinfection. Hall said there is no means of treatment and no vaccine that successfully immunizes cattle against the disease.
“In herds managed for a short breeding season, trichomoniasis can result in as much as a 50% decrease in the calf crop,” stated Hall. “In herds where the breeding season is long, there is potential for an extended calving period resulting in lower average weaning weights.”
According to Hall, control of trich focuses on the bull, through testing to identify infected animals. Smegma consisting of exudate and sloughed skin cells is collected from the surfaces of the penis and sheath. For a culture test, smegma samples are introduced to a culture medium, sent to a laboratory and examined for the presence infective protozoa. An alternative PCR test involves testing the sample for the presence of DNA from the infective organism.
Hall said regulations to help control the spread of trich vary among states. In Oklahoma, all bulls entering must post negative results from one PCR test or three culture tests. Bulls changing ownership with the state also must be tested unless they are going to slaughter. Virgin bulls under two years of age are exempt from testing requirements.
“To protect their herds from trichomoniasis, producers should practice good biosecurity measures. Use good management and keep good records,” advised Hall. “Buy only virgin bulls. When buying replacement females, buy virgin heifers rather than cows.”
Hall spoke during Thursday’s ARSBC session focused on fertility in the male. For more information, visit the Newsroom at www.appliedreprostrategies.com to view his PowerPoint, read the proceedings or listen to the presentation.
Comprehensive coverage of the symposium is available online at www.appliedreprostrategies.com. Compiled by the Angus Journal editorial team, the site is made possible through sponsorship by the Beef Reproduction Task Force.
Editor's Note: This article was written under contract or by staff of the Angus Journal. To request reprint permission and guidelines, contact Shauna Rose Hermel, editor, at 816-383-5270.