Bull breeding fitness tests essential for spring turnout

By Scout Nelson

At Kansas State University's Beef Cattle Institute, experts emphasize the importance of a fitness test known as the breeding soundness exam for bulls, particularly before they are turned out to breed in the spring. K-State veterinarian Bob Larson and Brian Lubbers recently discussed these exams on the Cattle Chat podcast, outlining what they entail and why they are critical.

According to Larson, "With that exam, we make sure the bull is in good body condition and that his feet and legs are sound." This exam also includes checking the bull’s reproductive anatomy and testing a semen sample to ensure he can effectively breed.

Lubbers added that the semen sample must show at least 70% of sperm cells with normal morphology and 30% with normal, forward-progressive motility for the bull to pass.

These tests are typically conducted in the spring, before the bulls join the female herd. Unfortunately, not all bulls meet the required standards on their first test, which can be due to a variety of reasons. Larson and Lubbers shared insights into what steps should be taken if a bull fails this critical exam.

“If he has a foot abscess, he will fail the exam but that is easy to treat and his prognosis of being able to return to breeding is good,” Lubbers explained, highlighting that some issues can be resolved, allowing the bull another chance to pass.

Larson noted that challenges like poor semen quality might be more problematic, stating, "If he only has 20% normal sperm under the microscope, he may never pass."

For younger bulls, particularly those around 12 months old who fail due to semen quality, Larson recommends a retest in a few weeks. He explained, “Because of the cattle breeds that we have in the U.S., I don’t expect all bulls will be fertile at 12 months of age, but by the time they are 15 months old, their age should not be a limiting factor.”

The discussions by Larson and Lubbers underscore the nuanced decisions that cattle producers must make based on the outcomes of these exams. These breeding soundness exams are pivotal in ensuring that only the most fertile bulls can breed, maintaining the herd's health and productivity.

Photo Credit -gettyimages-steveoehlenschlager