How did artificial insemination increase the influence of genetically superior dairy bulls?

Artificial insemination has significantly increased the influence of genetically superior dairy bulls by allowing their desirable traits to be passed on to a much larger number of progeny than would be possible through natural mating.12

In natural breeding, a single bull might typically mate with 30 to 50 cows annually. In contrast, through artificial insemination, a single bull can be used to inseminate thousands of cows—sometimes 10,000 or more—in a single year. This is made possible by the ability to dilute, deep-freeze, and store semen for long periods without losing its fertility.12

This process is integrated into rigorous progeny testing programs. After young sires are evaluated based on the performance of their daughters, the top-performing bulls are selected to be used extensively across the population. Because approximately 70 percent of dairy cattle are bred using this method, these selected sires effectively control the genetic destiny of the industry, leading to consistent genetic gains in milk production over time.3