(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.