Integrating New Techniques for an Improved Reproduction Program

Currently, reproductive failure is the first reason for involuntary culling, which stresses the economic importance of improving fertility. Estrous synchronization programs have been researched extensively since the mid 1990’s (Pursley et al. 1995; Moreira et al., 2001; Dewey at al., 2010) with the main objective of improving artificial insemination (AI) submission rate, decrease intervals between AI, reduce days open and improve overall reproductive performance. One major impediment to adequate reproductive performance is the reduced estrus detection rate, also known as AI submission rate. However, many dairies utilize estrus detection within a timed AI (TAI) protocol in order to reduce costs and possibly improve fertility. Until recently, research focused on evaluating fertility to TAI without considering the effects on estrus detection and overall fertility (i.e. both fertility of estrus detected and TAI cows) to the entire reproductive program. This may lead to false conclusions and recommendations since fertility may be drastically changed due to whether a dairy is utilizing estrus detection. In research studies in which cows are allowed to be inseminated in estrus during the ovulation synchronization protocol, rarely was fertility of cows inseminated in estrus reported and included in the overall reproductive performance of the programs being tested. In addition, initiation of resynchronization programs occurs at or before non-pregnancy diagnosis which can have implications on number of cows detected in estrus depending on how early nonpregnancy diagnosis occurs. Of recent, activity monitors have grown in popularity as a tool to improve estrus detection and questions have been raised to whether these are an additional tool or a replacement for synchronization programs.