This document discusses methods for estrous synchronization in cattle and sheep. Estrous synchronization aims to group females for calving, shorten breeding seasons, and reduce estrus detection. Key methods include using progesterone-releasing implants, pessaries, or feeding melengestrol acetate to extend the luteal phase. Prostaglandins are then used to induce luteolysis and estrus. Common synchronization protocols for cattle include Ovsynch, which uses GnRH and PGF2α, and CIDR-based protocols. Vaginal sponges and CIDR implants of varying durations can also be used in sheep and goats.