You know your horse needs a lot of fiber — actually, the majority of his calories should come from fiber — or he’s going to have digestive problems. And when you think fiber, you think hay. But chewing hay is something the older horse may find challenging.
To make things even more difficult for older horses, efficient fiber digestion also requires a thriving population of gut microorganisms, another area where the older horse will likely fall short.
Use pelleted or extruded complete feeds, you say. Yes, that’ll solve the chewing problem, but he’s still got to digest and absorb them. Feed fat, you say. Yes, fat is easily digested, but it only provides calories and can interfere with fiber digestion, something the older horse can’t afford.
The solution is to go back to hay, but find a type your horse can chew.
Horses that can’t chew hay efficiently may do well on a few pounds per day of chopped forage. Chopped forage is expensive, but it’s tasty and easily chewed. You can fill in with pelleted complete feeds to make up any differences, but you’re still getting that natural fiber.
If this isn’t enough, you can soak the chopped forage product before feeding, as the water will also soften it somewhat so that the horse’s chewing efforts may be more productive. For horses who think soaked hay is best tossed in the manure pit, try soaked hay cubes, as most horses don’t mind that they’re soaked.
If all else fails, try oat or soybean hulls. Many of the newer “lite” or “low-calorie” complete feeds make use of these highly nondigestible fiber ingredients and are a reasonable substitute for the hay portion of the horse’s diet. They’re also often mineral- and vitamin-enriched.
The best way to determine the feed you choose will provide fiber of a similar type to the fiber in hay is to call the manufacturer and ask what the ADF, or acid detergent fiber, level is. The “fiber” percentage on the label isn’t what you need to know. You want the ADF. Your target is about 30% ADF.
Aim to feed your horse chopped hay or an equivalent fiber source at a rate of about 1% of the horse’s ideal body weight per day. In other words, 11 lbs. per day for a 1,100-lb. horse.
At this rate, your horse will get about half the calories he needs from as close to a high-fiber, natural source as you can get. Additional calorie needs can be met by concentrates such as grain or brans, or ingredients high in easily digestible fiber, like beet pulp.
Beet pulp or beet-pulp-based processed feeds are a good choice because beet pulp is well tolerated by horses with sensitive digestive tracts, is well digested and itself helps to encourage healthy populations of organisms in the large bowel.
Horses that are poorly tolerant of grain can be maintained equally well on a combination of beet pulp and rice bran or wheat bran, which is especially useful since it is fed as a mash and doesn’t require much chewing (see October 2002).