Strategies to Improve Reproductive Efficiency: Fertility of Heifers Following Synchronization with a Timed AI Protocol
The continued downward trend in reproductive performance clearly indicates problems in U.S. dairy and beef herds. The failure to detect estrus in a timely and accurate manner is one of the most common and costly failure of AI programs and perhaps the major limiting factor of reproductive efficiency in many herds. Another major limitation to the success of an estrus synchronization program is the presence of anestrous or prepubertal heifers in the breeding herd which has also limited the use of AI in heifers. The over all goals of this research are to 1) improve the reproductive efficiency of dairy and beef heifers through the enhancement of timed artificial insemination (AI) programs and 2) investigate the physiological mechanism(s) by which further enhancements may be achieved. Age at first AI service and age at first calving can be managed
more precisely through the combined use of estrus synchronization protocols and AI. The development of methods that effectively synchronize a fertile estrus in heifers is needed to increase the use of AI and enhance the genetic merit of dairy and beef herds. Systematic breeding programs are the only practical means for providing an organized and efficient approach to improving reproductive efficiency and increase the economic return of artificial insemination (AI) in beef cattle operations.