Typical Mare

The reproductive cycle – part one.

- Hayley Kruger

The fight for survival is the strongest instinct for the horse, and one of the factors contributing to survival is producing offspring. Reproduction is thus a strong drive for the horse. Small wonder then that your mare’s reproductive cycles may produce pretty obvious signs, and her attention when in season (also known as ‘in heat’) is not primarily focused on you. Understanding what’s going on, and the timing, can help you deal with it more effectively.

Background

A mare reaches puberty at the average age of 18 months, but it can be as early as 10 and as late as 24 months. Although a filly can conceive at an early age, like a teenager she may be too immature to handle having a foal and the pressure of being a mother. The older mare also shouldn’t be put in a situation of having a foal if she cannot handle it. Fertility begins to decline from age 15 to 21. Other factors affecting fertility is the mare’s condition – the healthier the mare, the higher her rate of conception. Genetics also play a big part, as well as characteristics and conformation.

The ultimate question about whether to breed with your mare revolves around the chance of her delivering a live, healthy foal. The mare should first be in a good state of health, as well as free from any disease or condition that could impact her fertility, conception and gestation. A mare’s gestation period is typically 11 months.

The mare’s cycle – in season

The mare’s cycle, as a normal mare being bred to a normal stallion and assuming she will conceive, is set out below (in very basic format). The goal of this cycle is to deliver a fertile egg into the reproductive tract, where it can be fertilised.