Fortified feeds are probably one of the most popular feeds utilized in the horse industry outside of forages. Why? Their development was born of a perceived need for a convenient way for horse owners to dump “complete” nourishment in a bucket for their horse a couple times per day. Western society was being taught that laboratory-designed “nourishment” (I use that term very lightly) was somehow better than anything nature could provide…and that soon extended to feeding our animals, including horses. The practice of feeding grain to horses has likely been around since humans first kept horses for food purposes…the grain being used to fatten up the horses. As the general use of horses changed from a source of food to means of transportation and then as “athletic machines”, the practice of feeding grains only intensified and became more widespread. And as horses began to be used to “serve” humans instead of feed them, the practice of restricting their movement (i.e., stalling) also became much more prevalent. The current incarnation of the racing profession took shape in the early 1700’s; it became a huge catalyst for the development of what we have today in the form of high energy feeds toward the goal of creating a horse “machine” that could run faster with more stamina.
Fortified (processed) feeds typically come in two different forms: pelleted and sweet feed; sweet feed in turn can come in the form of either pellets or textured feed (meaning one in which the particles are visibly different). While almost all fortified feeds contain varying amounts and types of grains (usually in a ground meal form especially for the pelleted feeds), they typically contain less grain than a pure grain mix if considered by the quantity of feed required on a daily basis. Fortified feeds can be “heavily” fortified with vitamins (many times synthetic) as well as mineral salts, resulting in a lesser overall quantity of feed required to achieve the same amount of caloric energy as compared to a pure grain mix – this is how the feed companies are able to market the “low grain” aspect. Sweet feed is what we will be discussing in this short article; however many of the same statements can be applied to grain feeding in general and especially to feeding in regular “meals”. Sweet feed, as its name implies, contains some kind of sweetener (typically molasses) to act as a binder and to make the feed concoction palatable to horses, hiding the unpleasant taste of the crude mineral salts and/or other ingredients. The cost of sweet feeds makes them an attractive option for many horse owners – they are a relatively inexpensive way to feed with most of the ingredients being sourced at their least cost. Horses can seemingly do well on sweet feeds as they appear to have more “energy”; many horse owners will report a nice “shine” to the coat due to various ingredients (perhaps flax and/or some kind of oil). But we will see that these appearances can be deceptive.
It is said that horses have a “sweet tooth”. Exactly where that saying got started I am not quite sure; however, they are physiologically designed to efficiently metabolize sugars as they are found in nature and ingested slowly over the diurnal period. The horse does not have the physiology to correctly process a load of sugared feed in two or three meals per day. According to Colorado State University, high sugar feeds can:
- disrupt normal digestion,
- exacerbate certain medical conditions, and
- lead to serious complications like colic and laminitis – two serious conditions that can strike any horse.
Processed feeds and large grain meals move quicker through the small intestine than do forages. This can have the impact of decreasing nutrient absorption across the small intestinal wall as well as potentially allowing some starches to escape to the hindgut. Any undigested sugars and starches that reach the caecum are rapidly fermented into lactic acid. While a relatively small and infrequent amount of lactic acid production within the hindgut is likely to not cause long-term adverse consequences, an ongoing situation or a suddenly large amount being produced can have dire consequences, resulting in a situation called subclinical (or hindgut) acidosis. Acidosis can also cause colic situations as well as lead to laminitis. Furthermore, a situation of continual subclinical acidosis can have effects on behavior; stereotypies such as stall weaving and wood chewing have been linked to the discomforts of acidosis in the hindgut. If we move back to the foregut, we can also see some very real potential issues that can be caused or precipitated by feeding these processed feeds: grain meals can generate more acid in the stomach than does forage; and increased amounts of hydrolyzation of starches in the small intestine allows for more glucose to enter the portal blood. The effects of too much acid in the stomach can lead to a condition (or set of conditions) called Equine Gastric Ulcer Syndrome (EGUS). The horse’s stomach is relatively small for his overall size; this is a physiological design based upon the evolution of his digestive system. The horse is simply not meant to eat large, infrequent meals; his entire digestive system functions at peak efficiency when he is allowed to trickle feed the entire diurnal period. The increase of glucose in the blood will trigger the increased release of insulin; if this scenario is maintained for any substantial period of time, there is the very real risk of causing a condition known as insulin resistance (IR), wherein the cells become “resistant” to the action of insulin “pushing” glucose into the cells for the purpose of energy. This eventually becomes a cycle of more insulin needed to keep trying to push the glucose into the cells until the pancreatic beta cells become exhausted. By that time, the horse can actually become diabetic.
Depending upon the individual metabolism as well as the complete ecology of the horse’s lifestyle, some horses will be able to maintain feedings of sweet feed for several years without manifesting clinical symptoms; other horses will become affected in a relatively short amount of time. One of the issues is that science has only relatively recently begun to make the connection between inappropriate nutrition (and sweet feed in particular) with various pathologies of the horse. Unfortunately, some professionals still do not see this connection and will continue to recommend sweet feed. Barbaro is one well-known example that comes to mind. Is the low cost of sweet feed really worth it in the long run?
Many in the equine performance (racing, etc) sector say that a grain mix or some type of fortified feed is necessary to maintain and deliver sufficient energy levels for their horse. This is simply not true; it is another one of those “customs” that have been handed down for generations without really understanding why. There is finally beginning to be some amount of research and studies into the aspect of utilizing forages for the performance horse. The ones I have read so far are supportive of the fact of feeding forages in the performance sector with at least a reduction in grain if not complete removal. I have come across a couple of studies utilizing haylage in this respect, and would like to see more such studies; given what I know about its nutrient density and its digestibility, I would have no issue relying solely on that with no grain whatsoever for sufficient caloric energy for very active horses. That being said, there are also ethical considerations surrounding the welfare of the horse – you can’t drive your car at 100 mph non-stop no matter how much quality fuel you put in it; by the same token you cannot force your horse beyond his physical capabilities, sustained by supplements or otherwise. Unfortunately, again, human desires and wants tend to displace the welfare of the horse. And as we see time and again, the nutrition is not the only aspect to the overall wellbeing of any horse, and this is no less true for performance horses that are typically stalled for large parts of their lives because they are either too valuable or they will get dirty, or some other implausible reason.
 Reagan, Sarah. Equine Nutrition: From a Species Appropriate Perspective. Knoxville, TN: Willow Oak Publishing, 2013