What quality is essential to assess in bulls during breeding soundness exams for successful mating?

Semen quality is essential to assess during breeding soundness exams for successful mating because it directly impacts the bull’s fertility and ability to breed cows effectively. High-quality semen is characterized by a good sperm concentration, motility (the movement and swimming ability of sperm), and morphology (the shape and structure of the sperm). These factors are crucial because they determine the likelihood of successful fertilization once the bull mates with a cow.

Assessing semen quality helps ensure that the bull has the capability to achieve pregnancy in cows, which is the ultimate goal of breeding programs. If the semen quality is poor, even if a bull has a good temperament, age, or breeding history, it may not be effective in producing offspring, thus affecting the breeding operation's productivity and success.

While temperament, breeding history, and age are also important factors and contribute to the overall assessment of a bull's breeding soundness, they do not directly influence the immediate biological ability to fertilize an egg, making semen quality the most critical factor in this context.