By: Stephen Boyles, Ohio State University Extension Beef Specialist
During cold and windy weather, producers need to be aware of the potential for scrotal frostbite in bulls. During normal winter conditions frostbite is not a common problem with breeding bulls, but prolonged exposure to extreme cold and wind increases the incidence of frostbite. If frostbite occurs it can cause bull infertility the next breeding season. It can occur in bulls that don't have adequate dry bedding or protection from the wind.
During cold weather, it is a good idea for bulls to have at least protection from the wind. Defects in sperm are proportional to the severity of the frostbite lesions, testicle adhesions and swelling of the testes. Older bulls, with lower hanging scrotums are more frequently adversely affected because they are not as able to pull their testicles up close to the body to keep them warm.
Blisters and scabs might be observed about three weeks after the frostbite happens. A scab may appear on the lower portion of the scrotum as healing occurs. Scabs will fall off in about a month, leaving reddish-pin scar tissue. However, the absence of a scab does not indicate that frostbite injury has not occurred.
Some protective measures such as windbreaks and good bedding during bad weather can help prevent testicle freezing. Make sure all the bulls can get out of the wind if you maintain multiple bulls. A wind break fence out in the lot might be considered if other bulls tend kick one of the other bulls out of the main wind protection area or barn. Bulls being trucked in cold weather should be protected, since traveling in an open truck creates a serious wind chill factor.
Evaluation of possible frostbite damage is best accomplished by a trained veterinarian performing a breeding soundness examination 45-60 days after the injury occurred. A semen evaluation performed earlier than this period will most likely indicate poor semen quality and could result in unnecessarily culling a bull that may produce satisfactory semen after healing has occurred.