Endocrinology of the Estrous Cycle in Cows

The estrous cycle in cows (Bos taurus) is a complex, hormonally regulated process that prepares the female for ovulation and potential pregnancy. Cows experience a non-seasonal, polyestrous reproductive cycle, typically lasting 18–24 days, with an average of 21 days. Estrous is the phase of peak fertility, marked by behavioural signs of heat and the release of a mature oocyte. The hormonal landscape during oestrus is finely tuned to ensure optimal conditions for ovulation and potential fertilization. Understanding the endocrinology around oestrus is essential for effective reproductive management in cattle, including artificial insemination (AI), synchronization protocols, and diagnosis of reproductive disorders.