Physiology and pregnancy of beef cattle

Abstract The establishment of pregnancy early in the breeding season is critical for lifetime production and longevity of a female in a beef herd. More specifically, a beef heifer should attain puberty prior to the breeding season, exhibit normal estrous cycles, ovulate a gamete capable of being fertilized, form a blastocyst capable of signaling its presence to the dam, complete placentation, initiate parturition. and return to cyclicity postpartum. The preceding physiological events during gestation are complex and occur over an extended period of time. Any interruption to these events can result in pregnancy failure and reproductive loss. The purpose of this chapter is to review the physiological mechanisms controlling the onset of puberty, estrous cycle, establishment and maintenance of pregnancy, parturition, and postpartum anestrus in beef cattle.