Older mares can become pregnant and carry foals to term into their 20s. One of the oldest mares recorded to give birth was a 42-year-old mare in Australia. However, the overall reproductive potential of a mare typically begins to decline by about 15 years of age. Pregnancy rate per cycle and seasonal foaling rate both decrease with age.
Read more of the article by By Dr. Patrick McCue in The American Quarter Horse Journal by clicking here
