Revisit Feeding Strategies as Horses AgeBy Kentucky Equine Research Staff · September 17, 2007
The care and management of old horses has been the focus of much scrutiny of late. The reason is obvious: horses are living much longer than they once did, and horsemen needed to know how to offer appropriate care. Horse owners owe a debt of gratitude to the researchers that have unfurled the mysteries of age-related issues. In the past several years, significant research time and dollars have been devoted to Cushing's disease, melanomas, insulin resistance, and other syndromes that tend to crop up among the older equine set.
Despite these advances, some horsemen remain unclear on what to feed horses that are creeping into their late teens, twenties, and thirties. But, when referring to horses, what defines “old”? More important than chronological age is an assessment of the individual horse. After all, you have probably been in the company of a 75-year-old person who is amazingly active, sprightly, and completely self-reliant. On the flip side, you probably have been around someone of the same age who is less vigorous and independent. As with humans, not all horses age identically.
In general, old horses can be classified into one of three categories based on body condition: healthy weight, underweight, and overweight. At first, these categories may seem too simply rendered, but you'll find that most senior horses fit neatly into one.
Healthy and Active
The easiest senior horses to care for, from a nutritional perspective, are those that are healthy and somewhat active. The horses in this subset maintain weight with no trouble and are sound enough of limb and wind to participate in frequent exercise. The expenditure of calories from exercise does not rob the horse of necessary body condition.
Nutritional requirements depend largely on the extent of exercise. A teenaged horse that is preparing for a run at an international three-day event in which he will be asked to gallop long distances will differ considerably from a western pleasure horse of the same age that is ridden lightly four times a week. Many nutritionists suspect that these senior horses can be fed much like their younger mature counterparts, with appropriate consideration, of course, being given to individual energy requirements.
Until these horses present a specific challenge, the best idea is to continue feeding them good-quality forage and a well-formulated concentrate in quantities that suit their energy expenditures.
Can't Pinch an Inch
No horse, regardless of age, should be underweight. There was a time not long ago where less knowledgeable horse owners would quickly dismiss weight loss as a manifestation of age. It was, oddly enough, more or less accepted that old horses would be underweight. While it's true that old horses often do lose weight, there is usually a reason for it.
The explanations for weight loss among these hard keepers are numerous. Reasons cited most frequently are dental inadequacy and gastrointestinal inefficiency.
If a horse drops weight on a diet that once kept it in moderate body condition, there is likely an underlying medical condition. To uncover such a problem, a thorough veterinary examination should be scheduled. Most veterinarians that are presented with cases such as this will evaluate liver and kidney function.
Senior horses that have difficulty maintaining weight often have dental problems. Regular floating and other maintenance by a qualified individual might keep some of those problems at bay, but for senior horses, one of the primary issues is tooth loss. Don't assume the horse has a functional mouth if you simply pull back his lips and find a full set of incisors. These front teeth are usually the last ones lost by aged horses.
The cheek teeth or molars, those found further back in the mouth, are the ones that affect the digestive capability of the horse. Because they are used to grind feed into small particles, they are essential in the digestive process. Inability to properly chew feeds might cause inefficient digestion in the gastrointestinal tract. The lifespan of these teeth is usually 20 to 25 years. By the time the horse reaches this age, there is a real possibility of some molars loosening and falling out.
If tooth loss is determined to be the cause of declining body condition, steps can be taken to ensure the horse is properly nourished. Horsemen often use processed complete feeds to nourish horses. Complete feeds are those that can be fed as the sole ration, and are usually composed of an energy-rich roughage base (dehydrated alfalfa meal and/or dehydrated beet pulp, for instance) with energy, protein, and mineral-vitamin supplements added. The cereal grains in complete feeds are often heat-treated, which increases the digestibility of nutrients.
Another alternative for horses with poor dentition is chopped hay. Chopping hay significantly reduces the amount of chewing necessary by the horse. Chopped hay should be premium quality, with alfalfa or a mixture of high-quality grass hay and alfalfa probably the best choices. If chopped hay is fed, a vitamin-mineral supplement should be offered. These supplements often come in the form of a pellet and can be moistened to increase palatability.
Some horsemen find that aged horses do well on alfalfa hay. While they are probably going to be unable to chew the stems, many horses with compromised dentition will shake or move the hay so that the leaves fall off the stems. The leaves are the most nutritious part of the plant, so in this regard horses are quite wise. The downside to this is the likelihood of wastage, but unsoiled stems may be fed to other horses with high-calorie needs.
Horses that require still further calories to maintain weight can be fed fat in the form of vegetable oil (corn oil, soybean oil, canola oil). It can be mixed into a complete feed or used to soften the pellets previously mentioned. Up to two cups of vegetable oil can be given in one day, though small amounts should be offered initially.
Although rare, there are horses that wear down their incisors sufficiently to hamper proper grazing. More often than not, these horses have been dedicated cribbers or wood chewers their entire lives. A complete oral examination will reveal this problem immediately. If the cheek teeth are in working order, good-quality hay might have to be substituted for pasture.
While the teeth are a good starting point in the evaluation of a senior horse, absorption of nutrients might also be a factor in weight loss. Without question, older horses were less efficient at processing their meals decades ago. This situation changed with the advent of more specialized and efficient deworming protocols, and today researchers see little difference in nutrient absorption between young and old horses. In some horses, however, nutrient absorption might decrease slightly as years pass.
Generally, as hard-keeping seniors age, their energy requirements increase. The solution becomes simple: add more calories to the ration. Forages recommended for these horses include high-quality timothy, grass mixes, or a grass-alfalfa mix (no more than 50% alfalfa). Well-fortified feeds made especially for seniors are also suggested, as they often contain energy sources that are easily fermented in the hindgut. Older horses might do better on multiple small meals a day instead of two larger ones. Ideally, each meal should contain no more than four pounds of concentrate.
Pinching More Than an Inch
On the opposite end of the scale are those senior horses that have absolutely no trouble maintaining their weight. This is primarily due to overindulgence on the part of the owner, perhaps from a fear that the animal will lose weight as it ages. For those horses that are simply being pampered, a reduction in calories with a simultaneous increase in exercise will help them slim down to a more appropriate body condition.
However, there are a few metabolic conditions such as Cushing's syndrome, insulin resistance, and chronic laminitis that tend to surface in older horses. If these horses require energy in concentrate form, they should be offered feeds with low glycemic indexes. Typical senior feeds may not be appropriate for these horses, as they would contain too much sugar.
Feeds with a low glycemic index have only a slight effect on blood-sugar levels, while feeds assigned a high glycemic index significantly increase blood-sugar levels. How do you find a feed that has a low glycemic index? Horse owners should generally look for feeds that are low in starch and high in soluble fat. If in doubt, contact a reputable feed manufacturer or equine nutritionist for direction.
So, into which category does your aging buddy fall: healthy, underweight, or overweight? Horsemen must be cognizant of the dynamic nature of proper nutrition. What is nutritionally optimal for a five-year-old Arabian gelding is probably not so for a 25-year-old Thoroughbred. Feeding strategies must be revisited often as horses enter into their third and possibly fourth decades of life.