Choosing The Best Time To Breed Your Mare

There are pros and cons to breeding your mare at different times of the year, says Dr Mac.

- Dr Mac.

While mares can theoretically come into season throughout the year, the breeding season in South Africa tends to start on 1 August, particularly for race horses, due to the time at which yearlings are generally auctioned at national sales.

Breeding is influenced by the length of the day, which gets longer towards springtime. This is a natural regulating mechanism that enables a mare to foal at the time of the year when there is sufficient grazing and she can produce enough milk to raise a foal. It is regulated by a protein hormone called melatonin.

Melatonin levels are lower during the daytime and higher at night. High levels of melatonin prevent the body from excreting gonadotrophin, which initiates the reproductive cycle.

As a result, mares usually come into season when the days get longer in spring. Those breeders who want mares to come into season before the beginning of spring can use lighting in their stables for an hour after sunset and an hour before sunrise. As soon as the mares start cycling, they can be mated. Mares generally gestate between 11 and 12 months.

AUGUST BREEDING