The Myth of Balanced Feeds
Some feeds claim (or at least strongly suggest) that they will provide your horse with everything he needs in terms of nutrition, and in the optimum amounts. In fact, many people are afraid to stop feeding grain mixes because they believe the horse's diet will then be unbalanced and/or the horse will miss out on nutrition.
What you need to understand, though, is that your horse's nutrition needs to be looked at in terms of everything he eats - both hay/pasture and what might come out of a bag. It may be true that what's in the bag is balanced, or even contains enough vitamins and minerals for a day at a certain level of feeding. But that doesn't make the whole diet balanced unless it's the only thing the horse is eating.
For example, the diet should ideally contain about twice as much calcium as phosphorus. If you're feeding alfalfa or your horses are grazing on a pasture with a lot of clover, they are getting way too much calcium compared to phosphorus - six times as much, if not more. Feeding them a grain mix that has a balanced 2:1 ratio won't help matters any. You would be better off feeding plain grains and wheat bran, which are naturally higher in phosphorus than calcium.
Have you ever heard the adage that all a horse needs is hay and oats? Do you remember when the major controversy was oats vs. corn, or when sweet feed and bran mashes were exotic?
Today, if you go to the website of just about any feed company, or to a feed superstore, you'll find an astonishing array of different feeds to choose from. Often, these are so varied and complicated that the manufacturers have to provide feeding calculators or other product-selection devices, and even then you may end up with 10 or more choices. "Low carb" is particularly trendy these days. What do you do? What does it all mean?
It's impossible to feed your horse a low-carb diet. The bulk of the calories, even in grasses and hays, is carbohydrate. What matters is the type of carbohydrate.
The carbohydrate in your horse's diet comes from sugars, starches and fiber. Fiber is a complex carbohydrate that the horse's intestines can't digest, but the organisms in his large bowel can. The horse then uses the byproducts of that bacterial and protozoal fermentation of fiber as an energy source. Fiber is further broken down into water-soluble (dissolves in water) and nonsoluble fiber, with the soluble fiber being much more easily fermented and therefore yielding more calories.
Sugars and starches are digestible in the small intestine, and most are broken down to glucose before being absorbed. The calorie yield from simple sugars and starches is higher than from most fibers, and grains or molasses are many times higher in sugar or starch than hays and grass.
More horses and ponies get grains/concentrated feeds than actually need them. But before going into that, it's important to remember that grains are not poisons and they do have a place. The horse is designed to eat grass, not grains, and should always be fed as much grass or hay as he can eat before you consider feeding grains.
In most cases, only the hard-keeper breeds like Thoroughbreds truly need grain on a regular basis, or horses that are in hard work. Even pregnant, nursing and growing horses can do well and hold their weight on minimal to no grain as long as their protein and mineral needs are also being met.
Unfortunately, owners derive a great deal of pleasure from "feeding" their horse a grain meal because the horses obviously enjoy it and look forward to it. Too much grain and too little formal exercise have led to an explosion of health problems.
Health Problems That Benefit From Reducing Sugar and Starch
This is a form of tying up where the horse has abnormal amounts of carbohydrate stored in his muscles. Draft breeds and Quarter Horses are most often affected. These horses usually benefit from reduced sugar/starch and high-fat diets. Feeds no higher than the 10% to 20% sugar/starch category and with the highest level of fat seem to work best, but additional oil may still need to be added.
These horses need more exercise and fewer concentrated calories from all sources - fat, sugar and starch. The best choice by far is hay only, with needed vitamin/mineral supplements. If the horse is picky about supplements, go with a low-fat, no higher than 10% to 20% sugar/starch, option as a replacement for grain, feeding only as much as you need to in order to get the horse to eat his supplements.
Growth and Joint Development
Some rapidly growing young horses have been found to have much higher and more prolonged rises in their glucose and insulin after a grain feeding, and this seems to correlate well with their risk of developing OCD (developmental disease). Since there's no good way to tell which ones are at risk without expensive testing, and they really don't need all that grain to grow normally anyway, it just makes sense to cut back on the sugar and starch for young horses. Growing foals should be fed a protein and mineral supplement that closely complements their hay, and either a 50:50 blend of beet pulp and oats, or straight beet pulp with 2 oz. of rice bran added per pound. If beet pulp isn't an option, one of the feeds noted in the chart as a good choice for growing horses can be used, with amounts adjusted to keep the youngster growing at a steady rate but never allowing him to become fat. Ribs should always be easily felt on a growing horse.
Insulin Resistance and Laminitis
These disorders call for the tightest restrictions on sugar and starch. While some can tolerate hays (and feeds) in the 10% to 15% sugar/starch range, others need to stay in the ultra low, 10% or less, category. Low sugar/starch hay and just enough beet pulp to get supplements in is the ideal diet. Beet pulp can be soaked ahead of time and put into plastic storage containers or plastic freezer bags and refrigerated at the barn so that barn help doesn't have to do the soaking. If that won't work, choose from one of the 10% or less feed options, but remember the bulk of the diet should be hay.
Obesity is the most common, and being overweight is no more healthy for a horse than for a human. At the very least it greatly overloads the horse's spine, joints and feet, makes it harder to breathe, makes his heart have to work harder and makes it more difficult to keep cool when working. Even more dangerous is that overfeeding grain has been identified as a risk factor for osteochondrosis (a disease of joint cartilage) in young horses, and can lead to laminitis in horses that are insulin resistant. (See Equine Diabetes, April 2005)
Since so much attention has been paid to the health problems related to grain feeding and high sugar/starch diets, feed manufacturers are scrambling to jump on the low-carb wagon. But not all feeds labeled "low carb" are the same. Far from it. Feed companies naturally want to market their product, and labels are eye-catching. But what's newest isn't necessarily the best, so you might want to contact your state university's animal nutrition department or a nutrition-knowledgeable vet you trust to get the best advice for your particular horse and situation.
To help you, we've grouped some of the "low carb" feeds into three groups according to how low carb they actually are. As you can see, there's a huge variation. Notice also that not all low-carb feeds are low calorie. In fact, most are not, and some pack even more calories than regular grain mixes. The table on page 56 lists some situations where cutting sugar and starch is advisable, and how to go about it.
Many horses can indeed benefit from having the level of sugar and starch in their diet slashed. But the best way to do it is often not to feed any concentrated feeds at all. Give the horse all the low sugar and starch hay he can eat with a protein/mineral supplement as needed, and he'll not only be healthier, he'll be happier too. If you still want, or need, a feed, remember that not all low-carb feeds are created equal.