Before the fall breeding season begins, producers will want to contact their local veterinarian and schedule a time for the bulls to receive a "Breeding Soundness Exam." This is an excellent practice each year preceeding the breeding season, but could be most important in years following very hot later summers. The extreme and persistent heat of this summer may have "heat-stressed" bulls as late as early September. Bulls that have been heat-stressed will require at least 2 months (from the conclusion of the stress) to fully recover. Examine the graph below that illustrates sperm motility in bulls that were heat stressed and then allowed to return to a thermo-neutral environment. As you can tell, the bulls returned to normal sperm motility after 8 weeks. This coincides with the length of time needed for the complete development and maturation of new sperm cells in the testes. If bulls were ill or injured during this time, the elevated body temperature may have lingered causing further delay in the return to normal.
Assessing the "breeding soundness" now, would allow producers
to make adjustments in the bull battery before the critical first weeks
of the breeding season. If a bull is likely to be a poor performer,
the producer has time to locate a replacement and not delay the start of
next years' calf crop.
