Q: How long is a mare’s cycle?

A: A mare’s cycle is on average 21 days. Each 21 days demonstrates a fairly fixed pattern of physiological and behavioural events that are under hormonal control. The cycle can be roughly divided into two phases:

1. Oestrous, when the mare is receptive to the stallion. This usually lasts between five and six days.
2. Dioestrous, when the mare will reject sexual advances from the stallion. This lasts for the remainder of the cycle (somewhere around 15-16 days).