Embryonic death in cattle

Successful calving follows survival of the conceptus through embryonic and fetal development. Based upon reviews by numerous authors, much of the loss of potential offspring in cattle is concentrated in the embryonic period, the first 42 days after breeding. This article covers the impact of embryonic mortality on success of pregnancy in cattle, and some of the hormonal factors involved in pregnancy losses during the embryonic period. To establish the relative importance of embryonic death in the final outcome of mating, brief consideration is given to conception rate and fertilization rate.