Q: My husband and I have a mare in heat. I had suggested that we use a 2 1/2 year old stud that we own. He said that the stud is too young and that the foal would probably come out with some form of defect. Is this true? I am having a hard time finding an answer to this question. Can you help?

—Shelly

A: Most colts are capable of achieving pregnancy in fertile mares by two years of age, and the capacity for producing sperm cells usually increases between ages two and five. For this reason, most serious breeders will not try to breed large numbers of mares with colts that are two years old. But in your situation, there is no reason not to try breeding your mare with your stallion. The chances for producing offspring with genetic defects are no different now than when he is more mature.