anestrus

At other times of the year, they will be anestrus.

Female mice housed together tend to go into anestrus and do not cycle.

Horses mate in spring and summer, autumn is a transition time, and anestrus rules the winter.

Most females enter an anestrus period during the winter and thus do not cycle in this period.

As the days shorten, the mare returns to the anestrus period when she is not sexually receptive.

Changes in gonadotropin secretion initiate the end of anestrus in females.

"Long day" breeders cycle when days get longer (spring) and are in anestrus in fall and winter.

The uterus becomes flaccid during anestrus.

"Short day" breeders cycle when the length of daylight shortens (fall) and are in anestrus in spring and summer.

Cats are polyestrous but experience a seasonal anestrus in autumn and late winter (Spindler and Wildt, 1999).

If females fail to farrow despite being anestrus and are sent to an abattoir, their uteruses should be collected and examined for affected fetuses.

However, equines who live near the equator, where there is less change in length of day from season to season, have no anestrus period, at least in theory.

Dams may return to estrus, fail to farrow despite being anestrus, farrow few pigs per litter, or farrow a large proportion of mummified fetuses.

Therefore, many breeding farms begin to put mares "under lights" in late winter in order to bring them out of anestrus early and allow conception to occur in February or March.