Your Reading List

Test Before Putting Bulls Out To Pasture

Livestock producers should have their herd bulls examined for breeding soundness before turning them out with cows this summer.

“Veterinarians across the state are reporting higher-than-average rates of bulls failing breeding soundness exams,” says Charlie Stoltenow, North Dakota State University Extension Service veterinarian.

This year’s harsh winter weather may be to blame for at least part of the problem, according to Greg Lardy, NDSU Extension beef cattle specialist. In addition, short feed supplies may have impacted nutritional programs that bulls received this winter.

“Poor nutrition can negatively impact semen quality,” Lardy says. “Bulls which experience frostbite to testicles also have a higher likelihood of failing the exams. The severity of the injury is related to the likelihood of recovery. The more severe the frostbite, the higher the likelihood semen quality is impacted.”

Even in cases where frostbite is not apparent, semen quality may be impacted, so testing each bull prior to spring turnout is imperative, Stoltenow says. Because spermatogenesis takes approximately 60 days, injuries may not be readily apparent immediately after the occurrence of frostbite.

A basic breeding soundness examination consists of the following procedures:

Physical examination of the animal;

Examination of reproductive organs;

Measurement of scrotal size;

Evaluation of semen.

“These procedures help the veterinarian determine whether a bull is physically able to breed cows and determine if there are abnormalities in semen quality and/or quantity,” Stoltenow says. “Most local veterinary clinics perform these examinations routinely.”

Lardy recommends that if a bull fails or is deferred on a breeding soundness exam, have the bull re-evaluated in two weeks. He also suggests that during those two weeks, bulls should receive a well-balanced ration containing adequate amounts of protein, energy, minerals and vitamins.

If possible, bulls also should be allowed to graze on pasture. This grazing activity helps the reproductive healing process in the bull.

Stoltenow and Lardy suggest producers consult their local veterinarian for additional recommendations.

“Without a breeding soundness examination, producers risk lower pregnancy rates due to the failure of the bull to settle cows,” Lardy says. “The risk is heightened in single-sire pastures where there are no other bulls to service cows. Given the severity of this year’s winter weather, a breeding soundness examination is an inexpensive insurance policy to guard against costly open cows this fall.”

About the author

Comments

explore

Stories from our other publications