February 2012 - Feeding the older horse

Many horse owners keep their horses until they are quite old, even when their use has become minimal. Generally, we estimate that a horse can be defined as “aged” or “old” from about 20 years onwards. As with humans, however, there are large individual differences in how well individual horses will function in a riding or sports environment as they get older.

The nutritional literature gives us no clear-cut evidence to confirm that aged horses have a lower energy requirement than younger horses. Similarly, the effects of aging on a horse's protein needs are not very well known, although a reduced ability in older horses to digest protein has been reported. Ask your feed supplier about the protein source in your concentrate. Proteins with a good amino acid composition will ensure that the horse is able to maintain its muscle mass. The amino acids lysine and threonine have been identified as important in this respect.

Information on possible changes in the mineral and vitamin requirements of aged horses is also sparse. Small declines in the utilization of phosphorus and an increased need for vitamin C have been noted. In general however, it can be assumed that the feeding of horses aged 20 years or more provides the same challenges as does the feeding of any adult horse, as long as the requirements for exercise and other activities are observed and taken into account.

It is common for older horses to experience problems with the chewing of roughages as their teeth wear and new bone and enamel are not replenished at a sufficient rate. When horses aged 20 years or more do start to lose condition, special attention should be paid to feed quality. In particular, hay and other dried roughages should be leafy and not too hard to chew. Accordingly, some horse owners prefer to feed haylage to aged horses, thereby compensating for a reduced ability to chew dry roughage.

As for the concentrate part of the ration, pelleted feeds or muesli mixes will need less chewing and will have higher digestibility than untreated grains. The addition of some vegetable oil in the ration will increase the energy content and help to prevent or reduce a loss in body condition.

As with all other animals, including man, the likelihood of developing disease in horses increases with age. Cushing's disease is more common amongst older horses, and has consequences for feeding, since it affects both appetite and metabolism. Cushing’s disease is a metabolic disturbance caused by too high secretion of a hormone from the pituitary gland, which in turn leads to an excess of cortisol in the body. Symptoms of Cushing's include weight loss despite increased appetite, swollen eyes, and the development of a long and dense coat. Cushing’s may also predispose for serious conditions such as laminitis and diabetes. Horses with Cushing’s have a poor toleration of sugar or starch. Care should therefore be taken to reduce or eliminate sugary feeds or grain-based concentrates. As long as the horse’s teeth are in good condition, rations rich in fibre should be fed, since these are predominantly digested in the hind gut, and only cause limited blood sugar rises after a meal.

In summary, there is no magic solution to feeding aged horses well!

Use your PC-Horse program to adjust the ration based on body weight and level of exercise. Observe any change in body condition closely if you own a horse in the age group 20+. If it loses condition, be careful to monitor the teeth, and match the feed quality with the capacity for chewing. Reduce the size of the ration if the horse gets too fat. Watch out for diseases. Cushing's syndrome, diabetes, laminitis and recurrent colic episodes all require the advice of a veterinarian and a feed specialist.

This article was originally written by Dr. Day Austbø.
Copyright: PC-Horse International - Norway 2012.
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