Name a sign of heat in female goats.

A sign of heat in female goats is characterized by physical and behavioral changes that make them receptive to mating. The swelling of the vulva is a prominent indicator, as it signifies increased blood flow and hormonal activity associated with estrus. Tail flagging, where the goat frequently moves its tail side to side, is a common behavioral expression of readiness to mate.

These signs are crucial for breeders, as they help identify the optimal time for breeding. While increases in vocalization or changes in grazing behavior may occur around the time of heat, they do not specifically indicate estrus as clearly as the swelling of the vulva and tail flagging do. Therefore, these signs are a reliable and recognized method for identifying when a female goat is in heat, facilitating targeted breeding efforts.