If you have a senior horse in your barn, chances are he's a much-loved family member that has been with you for many years. Older horses can be a blessing, but as they age they might face significant feeding challenges that make it difficult for them to maintain a healthy weight and body condition. This article will address some of those common challenges.
As a horse ages, he gradually wears down the grinding surfaces of his teeth--and while the teeth continue to grow throughout a horse's life, often their wear and tear outstrips the replacement rate. Past his mid-20s he might literally have reached the end of the line when it comes to the roots of his teeth; the remaining little nubs are often loosely anchored in his jaws and prone to being lost or broken. This compromises your horse's ability to graze and chew. In very old horses the teeth might become so worn that they are practically nonexistent, leaving the horse with a limited ability to take in nutrients.
"One of the biggest issues I see with older horses is dental problems," says Mary Rose Paradis, DVM, Dipl. ACVIM, associate professor of Large Animal Medicine at Tufts University's Cummings School of Veterinary Medicine. "It's part of the aging process, unfortunately. We see more (esophageal) chokes and more large colon impactions because (older horses) can't grind their food down sufficiently. Dental issues are a major precursor to other health problems."
Reduced Digestive Efficiency
An older horse's laid-back temperament and (usually) modest energy expenditures mean his need for calories will be less than it was in his early years. But this is offset by a gastrointestinal (GI) tract that gradually becomes less able to process and extract nutrients from feed. As a result, the GI tract fails to absorb many essential dietary ingredients--such as protein, phosphorus, and several vitamins--that instead pass through the body untouched. Older horses also experience a decrease in stomach acids and enzymes that aid digestion, which leaves them less able to digest fiber (that all-important hay or pasture that forms the bulk of the diet) and starches. In addition, the digestive tract's motility is often compromised, making these horses more vulnerable to impaction colic.
Pasture is less problematic than hay for an older horse to digest, as fresh grass is higher in moisture, lower in indigestible fiber, and easier to break down in the GI tract even if it is only partially chewed. Protein, on the other hand, appears to be particularly challenging for geriatric horses to digest, especially if the digestive tract has suffered long-term parasite damage. Even when the diet supplies adequate protein, compromised digestion can lead the horse's body to act as if it is protein-starved. The result is muscle tissue wastage, as the body breaks down muscle to release protein back into the system for other important body functions. The sunken hips and swaybacks of many senior equids are examples of this muscle wastage. According to National Research Council (NRC) recommendations, an ideal geriatric diet will compensate for the decreased ability to digest protein by supplying higher protein levels and a high-quality amino acid profile; soybean meal is one good protein source that accomplishes both of these things.
A number of psychological factors might contribute to weight loss in senior horses. These horses often become passive because they no longer have the strength or inclination to stand up for themselves--so when they are fed in a group situation with younger horses, they might be pushed aside. Other stressors, such as long-distance shipping or even water that is too cold (causing tooth pain) might make an older horse lose enthusiasm for his feed.
You can help reduce many stress factors with basic management changes, such as turning your older horse out with similarly aged horses, rather than rambunctious youngsters. At feeding time, isolate him in a paddock or stall so he doesn't have to compete for his meals. Keeping his appetite up is crucial because putting weight back on a skinny older horse can be a struggle.
Weather extremes can be particularly difficult for geriatric horses. Because they have a harder time regulating their internal temperatures, they require more energy to stay warm in winter conditions. In cold weather a horse over the age of 20 might need to have his feed intake increased by 20% to help him maintain condition. Blanketing an older horse and providing a windbreak in his pasture also will help protect him from weather extremes.
Developing a Diet
There are three primary considerations when planning your older horse's diet:
- Ease of chewing;
- Improved nutrient availability; and
- Good palatability.
As your horse's ability to chew and digest fibrous, stemmy hay declines, it's increasingly important to provide him with good-quality pasture and more easily chewed and digestible forms of fiber. Choose a high-quality, soft hay with a fairly high legume content (such as alfalfa). (As a test, grab a handful of the hay and squeeze hard--if it hurts your hand, it's likely too tough and fibrous for your old guy.) The extra protein in a legume hay (as opposed to a grass hay such as Bermuda or timothy) can help offset your elder horse's decreased protein absorption.
A day might come when chewing even high-quality soft hay is too much of a chore for an older horse. In this case you might have to do some of the chewing for him, so to speak. This is when hay cubes or pellets become essential. Either can be soaked in warm water for an hour or two before feeding to make a gruel or a soup. (It's better to soak these products because hard cubes or pellets, incompletely chewed by an older horse, can leave him vulnerable to choke.)
Sugar beet pulp is another excellent fiber source for older horses. Once soaked, it's soft and very easily chewed (suitable for even the most toothless geriatric), extremely digestible, and calcium-rich. You can even serve it warm in the winter months, and its texture makes it a great place to hide any medications or supplements your horse might need.
The digestive tract's decreased efficiency also means that most senior horses will need the concentrated calories of grain to help maintain their condition--and a commercial pelleted or extruded ration is usually better than unprocessed whole grains (which can be difficult to chew). Pelleted and extruded rations are made with finely ground grains, so in a sense they are "pre-chewed." They are also exposed to heat, which makes some nutrients more available and easier to absorb.
In addition, pelleted feeds are easy to soak in water so that a toothless horse can consume the resulting mush.
Probably the easiest way to meet an aging horse's nutritional needs is to feed a ration formulated especially for "seniors." These feeds are manufactured with a softer-textured pellet format and an appealing taste. According to NRC recommendations, look for a grain mix that provides about 12-14% crude protein (a little higher than the level recommended for younger mature horses), 0.3% phosphorus, and a calcium level of at least 0.3% but not more than 1.0%, on a dry matter basis.
"Senior feeds are doing an excellent job of meeting the nutritional needs of older horses," says Karyn Malinowski, PhD, director of Rutgers University's Equine Science Center. "Between having these feeds available and the improved health horses now enjoy ... I think we can expect to see an increase in the percentage of horses or equine animals who live to a ripe, old age."
Feeds with added fat are another way to supply concentrated calories. Fat, in the form of vegetable oils or rice bran, is ¬highly digestible and contains almost two-and-a-half times more energy than carbohydrates. You can top-dress vegetable oil to a level of up to two cups per day, or you can buy a feed formulated with extra fats (look for a feed tag that lists a crude fat level of at least 5% and preferably up to 8%). High-fat feeds are contraindicated for horses with liver dysfunction (see sidebar).
Be willing to experiment to find out what your older horse likes and what he finds easy to eat. Cater to his dwindling food interest by offering smaller meals more often. With a little extra TLC on the nutritional front, most geriatric horses, even the relatively toothless, can lead healthy and productive lives for some time to come.
About the Author
Karen Briggs is the author of six books, including the recently updated Understanding Equine Nutrition as well as Understanding The Pony, both published by Eclipse Press. She's written a few thousand articles on subjects ranging from guttural pouch infections to how to compost your manure. She is also a Canadian certified riding coach, an equine nutritionist, and works in media relations for the harness racing industry. She lives with her band of off-the-track Thoroughbreds on a farm near Guelph, Ontario, and dabbles in eventing.
POLL: Tack Shopping Choices