Maximising foal heat fertility

The foal heat or first post-partum oestrus occurs usually begins between 5 and 12 days from foaling with the majority of mares ovulating by 20 days. Ovulation may be as early as 7 days. The main advantages of mating at the foal heat are ensuring the mare does not gradually foal later and later each year and that she remains fully productive. Mating at the second or 28-day oestrus cycle, especially if gestation is more than 11 months, means the mare must conceive if she is not going to gradually foal later each year. Some studies have not found lower pregnancy rates between the first post-partum oestrus and later oestrus cycles [1]. Timing of oestrus is well-defined and more easily detected. Finally, for those mares that foal early in the breeding season and may then become anoestrous after the foal heat ovulation the associated delay, which may be considerable in some individuals, is avoided ...