Farm location, breed, parity, and BCS had a significant influence on the proportion of cows that displayed estrus between P4 device removal and TAI.Because the occurrence of estrus is indicative of a successful synchronization response, differences between farms in occurrence of estrus may be an important aspect that can predict pregnancy outcomes in TAI programs in Bos indicus cattle. Differences within herd composition, such as the proportion of primiparous and multiparous cows, presence of crossbred cows, and proportion of cows with low BCS at the first day of the synchronization protocol, may be related to this disparity.