Feeding the Older HorseBy Kentucky Equine Research Staff · July 8, 2011
Dietary fiber is the most important consideration when designing a diet for old horses, particularly those with dental problems. Horses with moderate to severe dental abnormalities will do poorly on a predominantly hay diet, particularly when the hay is of low quality. Their inability to thoroughly chew will impair assimilation of energy and other nutrients from the feed, the result being progressive weight loss.
Ideally, the older horse should have daily access to pasture as grass is easily chewed and digested, and even horses with poor dentition can do reasonably well during the spring and summer months when given plenty of grazing time. An exception would be the horse that has damaged or missing incisor teeth.
Horses with poor dentition will usually require alternative fiber sources to ensure adequate fiber intake. Some horses will still have difficulty chewing hay cubes. In some cases, presoaking the cubes will aid mastication.
Horses with very poor teeth are sometimes unable to properly digest the fiber contained in hay cubes or chopped hay, simply because they cannot adequately chew the ingested material. Mushy feeds such as soaked hay pellets or beet pulp can be used in these situations.
An easy method for provision of dietary fiber is the feeding of a complete feed. Most of the senior feeds on the market contain a fiber source such as alfalfa meal, soy hulls, beet pulp, or a combination of these ingredients. These feeds also contain grains which have either been extruded or processed into other highly digestible forms (e.g., rolled, steam-flaked). These pelleted or extruded feeds are easy to chew, thus helping to prevent problems associated with poorly chewed feeds. For horses with very poor teeth, it is recommended that these feeds be soaked in water prior to feeding.
A well-formulated senior feed should contain, at the minimum, 12% dietary fiber and a protein percentage between 12 and 16%. The latter is often achieved by including soybean meal in the formulation. If there is evidence of decreased renal function, protein content should not exceed 12% and excess calcium should be avoided. Yeast and other digestive aids are also included to improve fiber and phosphorus digestion. Mineral and vitamin fortification should be higher than that for a standard maintenance horse feed to account for a possible age-related decline in digestive efficiency.
Oils such as corn, canola, and linseed are often added to commercial senior feeds. If more calories are required, additional oil (e.g., 100-150 ml or 3.4-5 ounces) or 1-2 lb (0.5-0.9 kg) of rice bran (20% fat) may be fed.
Although these diets can be fed without other forage, it is always preferable to provide the horse access to some high-quality forage in the form of pasture or first-cut hay with a high leaf-to-stem ratio.
It is generally necessary to feed older horses by themselves; in group situations, the younger, more dominant horses will often drive the older horse away from feed, contributing to weight loss problems.
Read more from Advances in Equine Nutrition III.