Synchronization of estrus and ovulation in cattle

Estrus detection has been cited as one of the most important factors affect ing the reproductive success of artificial insemination programs. Various e strus synchronization protocols have been developed to bring a large percen tage of groups of females into estrus at a predetermined time. Earlier prot ocols have involved controlling estrous cycle length in cattle either by ex tending the life span of the corpus luteum by the use of progestogens or sh ortening the life span of the corpus luteum by the use of prostaglandins. T he reduced fertility following the earlier synchronization protocols made i t necessary to understand ovarian follicular and corpus luteum dynamics in cattle. An increase in this basic understanding as well as the development of treatment regimes to manipulate ovarian follicular and corpus luteum dyn amics over the last decade have resulted in development of better estrus sy nchronization protocols based on a) elimination of the dominant follicle an d initiation of new follicular wave, b) initiation of new follicular wave, synchronization of ovulation and timed artificial insemination. These proto cols are very promising and have the potential to enhance pregnancy rates a nd the success of artificial insemination programs.