Anthropomorphic Feeding

(This is an excerpt from my book, Equine Nutrition: From a Species Appropriate Perspective.  Please note that the following discussion applies to healthy horses, not sick/debilitated ones.)

A little recognized aspect of the nutritional ecology of the horse is that they have evolved to be able to adapt to varying planes of nutrition.  What is a “plane of nutrition”?  A plane of nutrition is defined as the quantity and quality of per capita food intake.  In practical terms, this means that the horse is perfectly adapted biologically to seasonal fluctuations in nutrient availability.  This does not translate into – “it is ok to feed my horse only one or two large meals per day”.  What it means is that the horse instinctively knows he is supposed to increase his nutrient intake – and thus likely his fat deposits – prior to winter.  When you see your horse put on a little weight in the fall, this is no particular cause for alarm.  By the same token, when you see your horse lose some amount of weight over winter, this again is not necessarily cause for alarm.  To contradict this natural biological process can have consequences that I think are not being given proper recognition.  When we disrupt these innate biological processes, we can begin to step into at least the realm of metabolic imbalance if not outright disease condition.  There has been much written about the biology of behavior, but too little about the behavior of biology as science has tended to take a Newtonian view that biological processes are “mechanized”.

Allowing the horse to actually lose weight over winter respects his natural biological processes.  Western civilization tends to be obsessed with diet, and overeating is an all too common occurrence.  This unfortunately carries over to the animals under our care; horse owners tend to panic when they see their horse losing some amount of weight over winter and will increase the quantity of feed to compensate.  This is foreign to the horse whose not-so-distance ancestors were completely adapted to a decreasing plane of nutrition over winter.  Those same horses also knew to increase their plane of nutrition prior to the onset of winter and would naturally gain weight during that time.  Modern day horse owners will then respond to this with either increased exercise (to get that weight off!) and/or reduction in amount of food.  All of this has the effect of being virtually the opposite of what the horse would naturally do left to his own devices.

It depends upon your viewpoint as to how you will attempt to “fix” the layers of imbalance that begin to creep forward from a biologically inappropriate diet: 1) if your viewpoint is more “conventional”, you will do or give something to suppress the symptom, make it go away so it doesn’t have to be dealt with; or 2) if you come from a more “natural” viewpoint, you will likely search the internet for a supplement that will address the symptoms your horse is showing. Neither option is addressing the underlying causal factor, but that is how the vast majority of horses today are managed. The only real, valid option is to return the horse to correct biological diet that respects the physiology of the species. The problem with doing so is that the human wants and desires get in the way…but most people call that necessity. So, I ask you – why is it necessary to continue racing a horse that is falling apart physically and mentally? Why is it necessary to continue breeding the mare that is showing signs of exhaustion simply because she is “valuable”? The equine industry – all aspects of it – has literally turned our horses into machines that we throw substances into which are derived from laboratory-designed nutritional values so that we can keep our horse “machines” going as long as possible. And both “sides” are just as guilty of this – meaning both the so-called conventional and alternative factions. We do not need to design another “holistic supplement”…we need to start feeding our horses according to their needs and desires! We have assigned human-centric qualities to our horses so that we can relieve ourselves of the guilt: “He loves to run…he ran his heart out”, speaking of the race horse as he was being whipped yet one more time. Yes, he literally ran his heart out.

Sweet Deception

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.[1]  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[2], 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.[3]  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.[4]  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[5] 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.

Importance of Proper Nutrition during the Healing Process: Proteins

Hippocrates (460 BC – 377 BC), a Greek physician and known as the “father of medicine”, talked extensively about how “food should be our medicine” and “our medicine should be our food”.  He was, of course, speaking of humans as he exemplified how proper nourishment can go a long way in healing.  The same is nonetheless true of animals.  You might say that this only pertains to “disease” conditions.  But it is no less important in the face of physical injury; the body needs the proper building blocks to repair the injured tissues.  All nutrients are important, but in this abbreviated article we will look primarily at protein and its importance during the healing process.

The central dogma of modern conventional biology states that the life processes are genetically controlled – called genetic determinism.  In other words, the dogma says that the health and the fate of the organism are determined by the genetic inheritance.  However, recent advances in cellular science are showing us otherwise:  Environmental influences can affect the behavior of genes and thus the environment affects cellular behavior.  This “environment” includes not just the external physicality but also the internal physiology, with the internal physiology being dependent upon the proper “fuel” to operate and repair itself.  That “fuel” for the horse is biologically appropriate nutrition.

Cells are comprised of proteins, carbohydrates, nucleic acids, and lipids; proteins are one of the major components (along with lipids) of all plant and animal cells, being involved in the growth and development – including repair –  of all body tissues as well as reproduction and immunity.  Proteins are actually chains of amino acids; when a horse ingests protein as a whole, his body breaks it down (called de-hydration synthesis) into the amino acid components, re-arranging them (sequencing & folding) as needed for any particular function.  Some amino acids are synthesized within the body (called non-essential) and some have to be derived from diet (called essential).  Proteins are labile; meaning they wear out with use and must be replenished.  If a particular amino acid is in limited supply or is missing (or has been “used up”), its particular action will cease.

Stress and injury can increase the body’s need for various amino acids (aka protein), including creating a dietary need for even those that are theoretically non-essential.  Research has demonstrated that insufficient protein can delay or even stop wound healing.  Keep in mind that wounds can be external as well as internal.  With regard to horses (especially those in the performance sector), many “wounds” manifest as tears in tendons and ligaments.

There are currently 20 amino acids that are referred to as “standard” and most plants contain all of these and thus are complete proteins.  Therefore, a biologically appropriate foraging diet for a non-stressed horse should be completely sufficient.  The caveat is that much of the Earth’s soil is depleted of the minerals necessary to allow the plants to make complete protein.  And so it may become necessary to supplement a complete protein:  bee pollen is one of the complete proteins found in nature; legume forages are another good source of proteins.  In the injured horse, this kind of protein supplementation can become a nutritional requirement.  Used along with other modalities (such as magnet therapy, etc), it can greatly speed healing time.

Care should be taken, however, to not feed protein in major excess of the horse’s physiological need.  High protein feed and supplements (such as those listed as 20% crude protein or more) are at best a waste of money, and if fed in the form of grain/concentrates can be devastating metabolically.  We are beginning to see some studies done with high quality forages – specifically haylage in at least one study – used in place of concentrates as protein/energy boosters especially in performance horses.  It has been my personal experience that a quality product such as an alfalfa haylage (which has a perfectly acceptable crude protein allowance of about 9%) is a completely biologically appropriate way to supplement a foraging diet.