The reproductive efficiency of dairy cows is at the very heart of successful dairying. Timely calvings are critical to herd performance. The first-service conception rate of dairy cows was approximately 65 percent in 1951 but dropped to 40 percent by 1996.
The decrease was widespread, having been documented in the United States, Ireland, United Kingdom, and Australia by the turn of the century.
In recent years to improve dairy pregnancy rates, updates to insemination protocols were designed to better synchronize heat. Yet, less than 50 percent of cows become pregnant at the first insemination, and a second insemination is required. Given the availability of many successful heat detection/ synchronizing protocols, a healthy uterine environment ultimately is required to ensure the embryo reaches term.
