We’ve already talked about getting your mare ready for breeding, making sure she is healthy, vaccinated and ovulating. Now let’s talk about stallions. Whether you are using a stallion on your own farm or shipping in semen from across the country, a viable foal depends on two healthy parents.

If you are breeding your stallion for the first time, start with a general wellness check before moving to the reproductive evaluation. Sounds strange when you talk of horses but you want a stallion that has the physical and mental aptitude to “deliver” semen when needed. A good pedigree or winning lots of competitions doesn’t always mean he’ll be successful at breeding. Does the stallion have an active interest in mares, can he perform under stressful conditions without getting overly aggressive with the mare or the handler?

A veterinarian’s physical exam should include a complete health and wellness check of the stallion and include palpation of the genitalia. Particular attention should be given to the back and legs as well as any conformation defects that could be inherited by offspring. Testicular development is an important characteristic of a breeding stallion as both should be descended and adequately sized (potential influence to sperm production) with no swelling (possible indicator of infection/painful) which could eventually lead to breeding difficulty. Stallions with a single descended testicle can still be fertile but this physical trait could be passed on to offspring.

There are pathogenic organisms that can cause venereal disease in horses – bacteria, viruses and protozoa should all be tested for by culture swab. There can sometimes be obvious signs of infection but more commonly, asymptomatic stallions carry and spread disease during breeding. A pre-ejaculate swab and a post-ejaculate swab will give indications of potential genital infection after culture in a lab.

Leg soundness is just as important as breeding soundness. When mounting, whether it’s live cover or a breeding dummy, all a stallion’s weight shifts to the back end. If a stallion has lameness issues or physical defects in the hind legs, the very act of breeding can be painful. You end up with a negative association with the act – if it hurts when he mounts, the stallion could lose his desire and refuse to complete the ejaculation.

Next comes evaluation of the semen itself – sperm morphology and motility, semen volume and sperm concentrate all should be evaluated. Are these new terms for you? Morphology is the sperm structure – are there any bent tails, coiled tails, abnormal heads, or detached heads. Motility is the viability of the sperm – can they move/swim progressively (in a straight line). Semen volume and concentrate deal with the total sperm per ejaculate.

5 Tasks from the Stallion Owner’s Perspective

  1. Make sure to give the stallion owner notification that you need semen by the deadline specified in the contract. Not every stallion spends the season at a collection station. Even if they do, it’s easier on everyone involved to be able to plan the day rather than rush to collect at the last minute.
  2. When booking a stallion please read the contract. Understand the guidelines the stallion owner has set beforehand to make the breeding season move smoother, including blackout/no-ship dates ahead of time.
  3. Get a uterine culture on your mare. Just because she is a maiden mare or is not exhibiting any outward signs of infection, does not mean that there is not an issue. Some infections (like E. Coli) are easy to treat but can prevent pregnancy if left untreated.
  4. If there is a problem with the semen, let the owner/collection station know (politely) as soon as possible, preferably as soon as it arrives. Please don’t yell at the stallion owner about the quality of the semen 3 weeks after the fact, when your mare comes up open.
  5. Check your mares on proper days. If a stallion’s collection days are Monday, Wednesday and Friday, you need to have your mares checked Sunday, Tuesday and Thursday.

Horses have been breeding without assistance for years but an annual physical and breeding soundness exam will give a better idea of how many mares could be serviced in a single breeding season. The information collected isn’t always precise but instead is an estimate of the stallion’s capability. As indicated previously, both stallion fertility and management partnered with mare fertility and management are both important to the business of foal production.

Brenda Jackson, Murray County Extension Coordinator