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Bull tests small investment in avoiding open cows

by Wyoming Livestock Roundup

Casper – “Trich can reduce a calf crop 40 to 50 percent, and that’s a scary number in a herd that hasn’t seen the disease,” said UW Extension Educator Hudson Hill from Lincoln County.
Hudson Hill spoke with UW Extension Educator Bridger Feuz on the economics of trichomoniasis during the 2009 Profitability Conference of the Wyoming Stock Growers and Wool Growers annual meeting.

“The strategies to avoid trich infections are don’t let infected bulls breed susceptible cows, and don’t let infected cows breed with susceptible bulls,” said Hill. “It sounds simple, but there’s no uniform success.”

“I look at trich – and it’s a sneaky disease,” he said. “Some things out there aren’t necessarily sound science. An infected cow may carry a full-term calf, and there’s one proven example where an infected cow carried a calf full term.”

Hill noted there also may be the possibility of bull to bull transfer. “I would propose there’s no such thing as a virgin bull,” he said, adding that young bulls constantly ride each other when they’re penned together. “It’s a real possibility they could infect each other.”

Wyoming State Veterinarian Jim Logan added there’s speculation that chronically infected cows – because one percent of infected cows never truly clear up, but become carriers – may infect their bull calves, so even a truly “virgin bull” could be infected by in utero transmission.

Feuz spoke on the cost/benefit analysis of trich and how cost is assigned to the disease.

“It boils down to open cows,” he said. “The other costs you can debate, but when we go through an analysis, it’s focused on open cows, which would apply to any management practice in reaction to a disease that would cause open cows on your ranch.”

The assumptions Feuz made in his analysis is that producers will maintain constant cow numbers, which will increase the heifers retained in the cowherd.

“Keeping open cows is a recipe for disaster, especially in a trich area,” said Feuz. “The economics on it don’t work out. You’ll rarely find a time where keeping an open cow until the next year will pay for itself.”

Feuz said there are three outcomes for each open cow – a producer can generate income from selling her, have a loss of income without having a calf to sell in the fall, and have a second loss of income from retaining an extra heifer to maintain herd size.

“You’re losing two sales of calves for each open cow you sell,” he said. “You’re selling the cow in the fall, but you’re not getting the calf revenue. You have some cost savings on raising that calf, but most costs from raising a calf are in annual cow maintenance.”

Feuz said the net loss at having one percent open cows, or one per 100 head, is $561.25 per open cow. “It doesn’t matter what management practice caused that, but trich can cause extra open cows,” he said.

At 10 open cows per 100 head, Feuz said it costs $5,600. At 40 percent open cows the cost is $22,450.

“That’s a significant cost, and there are additional costs in terms of poorer breedups with later and smaller calves,” he added.

“To avoid the disease you need to have a comprehensive management plan,” said Hill. “Good fences make good neighbors, and the more we can separate and keep our cows at home, the more we can avoid the disease.”

Hill added it’s important to sell open cows to slaughter, and test all bulls, at least when they come onto your place.

“A bull test is $35 per test, plus some extra costs including labor,” said Feuz. “At four bulls per 100 cows, that’s $200 to test the bulls. For every one percent in open cows you avoid by testing the bulls, that’s $361 profit. If you can make a 10 percent reduction in open cows, that’s a gain of $5,400. It’s a pretty small investment in testing bulls in comparison to what an open cow will cost you.”

“Purchase only virgin, tested bulls and heifers from reputable sources,” said Hill. “Keep bulls as young as possible, because older bulls can harbor the organism better.”

Hill suggested using AI when possible, and having a defined breeding season because trich can go unnoticed in continuous breeding systems.

Christy Hemken is managing editor of the Wyoming Livestock Roundup and can be reached at

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