As we prepare for the breeding season or for those in the midst of the breeding season, it is important to think about how we can manage bull fertility and understand critical factors that can impact fertility. There are many factors that can affect sperm production; however, the main factors that can decrease sperm production are disease, fever, injury, and extreme environmental conditions. We must keep in mind that spermatogenesis, the production of sperm, is a 61-day process in bulls; therefore, it will take upwards of 60 days to have normal sperm again following an injury/insult.