Estrus, also known as heat or oestrus, is a specific phase in the reproductive cycle of female mammals where they become sexually receptive and fertile. It is characterized by a series of physiological and behavioral changes that are triggered by hormonal fluctuations.
During estrus, the hormone levels of estrogen rise, leading to the development and release of eggs from the ovaries. This period typically occurs at regular intervals, ranging from a few days to a few weeks depending on the species. The onset and duration of estrus can differ between different animals, with some displaying overt signs such as vocalizations, increased activity, and physical changes like swelling of the genitalia or discharge.
The primary purpose of estrus is to signal to male animals that a female is sexually available for mating. Consequently, males of the same species often exhibit heightened sexual interest during this time, engaging in courtship behaviors and actively searching for potential mates.
Estrus plays a crucial role in reproductive success, as it allows for the fertilization of eggs by sperm and subsequent reproduction. In species that are seasonal breeders, such as some deer or wolves, estrus may only occur seasonally or during specific times of the year.
Understanding the different stages of estrus is essential for efficient breeding programs, as well as for managing and controlling animal populations. Veterinarians, researchers, and animal husbandry experts often monitor estrus cycles to ensure successful reproduction and facilitate genetic improvement in domesticated mammals.
