"Hay, oats and water" is what the old timers often say when the subject of nutrition comes up, and the younger generation tends to snicker, "Maybe in your time, gramps." But there is a wisdom there that won't go out of date. Regardless of the particular ingredients you choose for your basic program, the quality of those ingredients is especially important. Do not depend upon supplements or concentrates to "make up" for poor quality feedstuffs. A successful nutrition program begins with careful, consistent monitoring of pastures, hay and grains for signs of rust, smut, molds and spoilage. The toxic by-products of molds and bacteria, or the organisms themselves, can cause a host of problems ranging from reduced growth to unexplained abortions to death. Feeds in which mold, spoilage or dust are present are simply unacceptable. Reject them without compromise. Make sure that grain bins are cleaned out before refilling and keep all stored feedstuffs as dry as possible. Some types of mold and bacteria are impossible to detect by eye. Ask your extension agent or feed consultant about local conditions and testing programs.
Another safeguard against contamination, and the first step in preventing dehydration, is to make sure the water you offer your horse is truly fresh and clean. Scrub the tubs clean every day and remember, if you wouldn't drink it, don't expect your horse to. (Don't confuse fresh with very cold, though, as cold water in liberal amounts can cause a recently exercised horse to colic.) Make sure that plenty of clean, fresh water is available at all times.
Assuring the quality of the basic feed is the first priority in a successful nutrition program. It will give you a solid foundation to build on, and make further improvements much more effective. To better understand the building of this foundation, we will take a quick look at the major nutrient groups in the feed. These are energy, protein and roughage.
The energy requirements of horses are affected by so many variables that it is impossible to make specific recommendations without observing the individual animal. Energy, sometimes called fuel, is derived mostly from carbohydrates and fats. Until recently, the focus was on carbohydrates, the dominant fuel provided by grains. Since hay yields a much lower amount of energy per pound, horsemen seeking extra energy reserves assumed they had to increase the proportion of grains in the diet. Other attempted "fixes" have included the addition of molasses, corn syrup and honey, all concentrated sources of sugars. Research is beginning to confirm the suspicions of many horsemen about this approach; high levels of quick burning sugars tend to put the horse into a cycle of energy highs and lows that results in reduced stamina and performance. But excessive feeding of grain poses a host of problems, too, some of which we will consider in a moment.
A new tool for energy management is added fat. A conventional mix of grains and hay will usually be under 5% fat. A number of studies have shown that horses can readily digest added vegetable oils or animal fats. The maximum amount seems to be about 15% of the total ration by weight. This approach overcomes several problems that can arise in the quest for extra energy.
Without fat supplementation, trying to keep weight on a "hard keeper" or attempting to boost energy stores during training, racing or endurance riding can tempt the horseman to tip the grain/hay balance into the danger zone.
Why do we say danger zone? First, too little hay or forage deprives the horse of the roughage he needs for efficient digestion and a healthy hind gut. (An exception to this is the use of special concentrates formulated with high levels of roughage from beets or other sources.) Second, a good deal of energy is used in the digestion of grains, and quite a bit of heat is released. Thus, excess grain can significantly raise the "thermal load" the horse has to contend with, an especially big drawback during hot weather. Fats generate significantly less heat during digestion. And third, extra grain means extra protein, which can lead to tying up and other problems. The increased risk of colic with a high grain diet is all too familiar to any experienced horsemen. Fats are a "pure" energy source. When you add them to the diet for energy, that's exactly what you get.
Grains are the major protein source in most feeding programs. The optimum protein intake is still a subject of fierce debate. Individual horses can have very different needs for daily protein. This variety is compounded by the dozens of different events we use them in. In short, the debate is not likely to end soon. But knowing some of the facts about protein metabolism can help you to design the right programs for the individuals you work with.
The standard way to evaluate protein intake is to look at the percentage of crude protein in the diet. This is generally a measurement of the nitrogen content of the feed. That's because, for the most part, only proteins in the feed contain nitrogen. A conversion factor is then used to estimate the amount of overall protein present.
But what is protein? Proteins are groups of amino acids linked together to form large molecules. These molecules are too large for the horse to absorb. So, after the teeth, saliva and stomach acids have done their part to break down the feed, enzymes released in the small intestine split apart the protein molecules into much smaller units. These are amino acids and peptides, which are very small groups of amino acids. Amino acids and peptides easily pass through the intestinal wall and into circulation. Once inside the body, they are reassembled to form proteins the horse's body can use to make blood, muscle, bone, skin, hooves, nervous system tissues and much more. They are even used to make more enzymes so more amino acids and peptides can be absorbed in the future!
When the horse's body makes proteins, it must follow an exact blueprint - no substitutions allowed. Each amino acid must be available to occupy its special place in the protein molecule. There are eight amino acids which are considered "essential" in the horse's diet. These are amino acids the horse's body cannot manufacture from other amino acids. If the body runs out of a specific essential amino acid, no more proteins can be made which require that amino acid. Say you're building a fence. You've got plenty of posts but you run out of rails. Fence building stops until you buy more rails. In nutrition, this is called the "limiting amino acid principle."
Unfortunately, the grains we feed to horses are poor sources of at least two of the essentials; lysine and methionine. In fact, oats and corn are so low in these amino acids that the percentage of available protein may be only half the crude protein percentage. Available protein is, roughly, the amount that can be used until the body runs out of one of the essential amino acids. Try roasted soy beans (45% protein and a great source of lysine) as a supplement to improve protein quality.
Take care in managing your feeding program and you will reap the rewards for years to come. And if you should come across a tough nutritional problem, the folks here at Vita-Flex (toll free 1-800-848-2359) will always be glad to help.