Reprinted with permission from the February 4, 2008 issue of Alberta Agriculture's Agri-News

The discovery of bovine trichomoniasis in Alberta cattle over the past few years has led Alberta Agriculture and Food to renew efforts to inform industry about disease control methods. The disease is caused by a parasite that is passed from bulls to females during breeding. Infected cows become temporarily infertile.

The reappearance of the disease, which was a problem in the mid-1990s, was detected by the Alberta Veterinary Surveillance Network (AVSN). "This is an example of how AVSN is working," says Dr. Gerald Hauer, assistant chief provincial veterinarian with Alberta Agriculture and Food, Edmonton. "The network is designed to pick up emerging diseases."

Losses to production can be large, as trichomoniasis can lead to a large percentage of females being open or calving late.

"In a single herd, the number of cows that are not pregnant at the end of breeding season can range from 30 per cent to as high as 70 per cent," says Dr. Jagdish Patel, veterinarian with Alberta Agriculture and Food's Food Safety Division.

"Herds that share bulls during the breeding season have the highest risk of contracting disease," adds Hauer.

There are tests that can be used to detect trichomoniasis infection in bulls. However, they only detect about two thirds on the infected bulls when only one test is performed. This is true of both the older culture methods and the new polymerase chain reaction (PCR) test. Conducting three tests at weekly intervals will increase the chances of detecting an infection in a bull to over 80 per cent.

Cattle producers are encouraged to develop and implement a Trichomoniasis Prevention Plan in conjunction with their herd veterinarian. Some management practices that reduce the risk of trichomoniasis causing a problem in your herd include:

• use only virgin bulls and heifers as replacements
• use as many home-raised heifers as possible otest all mature bulls at least three times at weekly intervals before introducing them into a herd, especially in shared grazing
• keep the average bull age as young as possible
• maintain a limited, tight breeding season
• buy only confirmed pregnant heifers if outside replacements are needed
• test cows that have recently aborted
• pregnancy check and cull open cows
• maintain good fences to decrease the chance of commingling of cattle

"Work with your herd veterinarian to develop the best strategy for preventing trichomoniasis," Hauer says.

For more information, contact Alberta Ag-Info Line 310-FARM (3276).