Are horses living longer? It seems so - at least - when it comes to broodmares. Assessing our breeding records for the past couple of years, we have seen an increase in the number of older mares being bred.

Generally speaking, older mares range between 18 and 26 years of age. This eight year period could mean an output of several more foals in the productive career of a mare.

Opinions volley back and forth on this issue of breeding older mares. On one hand, some folks believe that later foals are not as vigorous as earlier foals and are therefore less valuable. On the other hand, if a mare has already produced outstanding individuals, the value of her offspring may be at a record high. In fact, the offspring from many older mares may be so valuable that the mare is in an embryo transfer program.

If the choice is made to continue breeding the older mare, good care is imperative to giving the best odds of producing a foal as healthy and vigorous as possible. This requires that the mare’s condition be maintained at its optimum level. This begins and ends with proper nutritional management combined with proper health management.

The first step in elderly nutrition is getting the older horse to consume specially designed rations. Having a palatable diet which will be eaten in sufficient quantities to supply balanced nutrition is often a problem. For example, many special diets for elderly horses contain relatively high levels of fat. The idea is that an older horse can eat less and get more easily digestible energy. But, if the horse reduces its consumption due to the high fat content, the purpose is defeated.

Another problem is the rejection of foodstuffs due to an inability to chew and swallow easily. To start with the teeth need to be checked at least every six months by an equine dentist. Routine floating of the teeth when necessary can increase the consumption of feed. With the teeth in the best possible shape, circumventing additional old age chewing problems can be solved by serving “partially chewed - up” feeds such as pelleted feeds or coarsely ground feeds. Moistening grain rations and/or hay rations may also help since reduction in chewing time due to bad teeth can reduce saliva production. A horse normally produces 10 gallons of saliva a day. (Saliva is 99% water) It takes 0.5 gallon of saliva to properly wet 1 pound of hay and it takes 1 pint of saliva to wet 1 pound of oats for swallowing.

Now that we have techniques to help the older horse consume its feed, the next step is to be sure that we have a diet that provides an adequate balance of nutrients. A ration for an older barren broodmare should be in the range of 20,000 - 25,000 calories a day. The combined protein level in both the grain and hay/grass should average out to around 12%. The quality of the protein is also important. Many older horses are protein-starved. If you are unsure about the quality of the protein in your feed, there are ways to top dress your grain ration - for example, with a commercial protein supplement or an half cup of milk replacer or an egg or two. In the area of vitamin and mineral nutrition, the geriatric horse may also have a special problem.

Even though the raw materials may be present in the diet to build the vitamins, the aged horse may have reduced capacity in the metabolic pathways for vitamin synthesis. Even if the vitamin or mineral itself is present in the feed, the older horse may have a lowered capacity for absorption. In such cases, extra supplementation can be beneficial. For example, xerosis, dry skin around the eye and xerophthalmia, dry eye ball, are both early signs of a vitamin A deficiency. Fish oils such as cod liver oil or liver extracts or injectable Vitamin A are possible supplement sources which can eliminate these conditions.

Gut motility is another consideration in the older horse. Just like in people, the amount of fiber in the diet influences gut movement. Unfortunately prunes are too expensive for horses but wheat bran is also a good source of fiber. Keep in mind that some studies have shown that bran looses its laxative effect if it is used over an extended period of time. This is because the horse’s gut adapts to the increased amount of fiber, a useful tidbit of information that also applies to human nutrition. Still, bran is an excellent component in the ration of older horses but it should be noted that bran chelates calcium. This means that bran binds up some of the calcium making less available for absorption. Therefore if a horse is fed a high bran diet, calcium levels in the ration should be increased.

Basically, it is a good idea to be sure that older broodmares are getting enough calcium in their diets. The National Research Council (NRC) recommends about 19 grams of calcium a day for a mature idle horse which is probably sufficient for an older horse. However, the recommendation for pregnant mares increases the requirement to between 28 and 31 grams a day. Supplementation may be necessary for older broodmares fed senior rations. These rations are not designed for pregnant mares. Calcium values also dramatically increase during lactation. These factors require particular attention needs to be paid to the overall quality and design of the grain fed to geriatric broodmares. All in all getting older mares in foal and having them produce strong vigorous foals which can compete with foals from younger mares requires an increased level of management but, at least, with horses we have the opportunity for older dams since mares do not experience menopause.

(The oldest mare we ever got in foal was 25 years old and she delivered a fine looking foal at 26. She milked fine and the filly grew off normally.)

Copyright 2006 Dr. Jim and Lynda McCall