Bulls – Breeding Soundness Exam (Semen Testing)
Evaluating bulls prior to the breeding season can prevent significant economic loss. This is especially true in small herds (most beef herds in Ontario) for a couple of reasons:
1. Each open cow represents a proportionately larger economic loss
2. There are fewer bulls (maybe only 1) running with the cows, leaving less room for error
It is much less costly and frustrating to identify a dud bull before the breeding season, versus at preg-check or calving time. A breeding soundness exam includes the following:
Physical & Ultrasound Exam | Evaluates the physical characteristics of a bull necessary for mobility in the pasture, structural soundness, and overall internal and external reproductive tract development. |
Scrotal Circumference | Evaluates testicular size and health, as well as estimating the bull’s sperm-producing capacity (minimum measurements based on age, breed) |
Sperm Motility | Ensures that the bull is producing sufficient live motile sperm |
Sperm Morphology | Ensures that the bull is producing sperm that are properly shaped and capable of fertilization |
A bull is then categorized as fertile, sub-fertile, or infertile (sterile). Infertile bulls are often easily identified and culled. Sub-fertile bulls are sneaky in how they drain your bottom line: even though they may eventually get cows pregnant, they will take much longer than fertile bulls. In other words: fewer calves + more later-born calves (lighter at weaning) = fewer pounds of beef raised per exposed cow.
If you have any questions on this or other topics, please do not hesitate to contact one of our Veterinarians.