by Lucas Habib

Reproductive efficiency is crucial to economic success in the cattle industry, and bull selection plays a key role. But a new study shows that Ontario farmers often overlook simple management strategies, such as routine breeding soundness exams (BSEs), that could help to improve efficiency.

Perth veterinarian Dr. Jim Ferrier was commissioned by the Ontario Cattlemen's Association conducted a field study on the state of reproductive performance in cow-calf operations; the results identify key areas in which efficiency could be enhanced, such as ensuring that both cows and bulls are as healthy as possible.

"We found a difference between the body conditions of cows and bulls," says Ferrier.

"But the bull is responsible for every calf born in the herd, so it’s important that he’s healthy."

For his study, Ferrier randomly selected 60 cow-calf farmers across Ontario and collected data from their farms during the 1999 breeding season through the following calving season.

He found that cows are generally well-nourished and that the stillborn calving rate is very low. The study also revealed that most producers have effective vaccination programs in place in order to keep disease status low.

But Ferrier also identified weaknesses and discovered that many problems within Ontario cow-calf herds are related to the management of the bulls. He found that 23 per cent of the bulls were lame and many more had poor-quality feet and legs. This affects the ability of the bull to service females and reduces the herd’s reproductive efficiency. Ferrier suggests this problem can be partially reduced if farmers ensure that the bulls have their feet trimmed prior to the breeding season.

The study also found that 27 per cent of bulls have a minimum or below-minimum recommended scrotal circumference. Since this problem is largely hereditary, Ferrier says there isn’t much that can be done to increase reproductive efficiency once the bull is part of the herd. But he recommends that farmers have a BSE performed on a bull before they invest in it.

A BSE can accurately predict the breeding potential of a bull, including scrotal circumference. Currently, only 14 per cent of farmers use this technology before purchasing a bull.

"Bull selection is a very important factor contributing to reproductive efficiency," says Ferrier. "Hopefully, farmers reading the report will begin to make better use of BSEs, which have the potential to be a huge benefit."