Nutritionist Q&A: FatsBy Kentucky Equine Research Staff · September 15, 1998
Q: I have been acutely aware of major shifts in recent years from low fat to high fat diets in our performance horses. From my perspective, it seems to be creating excellent results in several classes of horses. I guess I'm a little concerned about where all this is going and what kind of research is being done to assure the long term health of our horses is being given adequate consideration. Do we have adequate research and understanding of what the impact of high-fat diets might be to their metabolism or to their overall physical development? Is there adequate follow up research being conducted to assure we are not creating something we have to deal with later in the life of these performers? I'm not an “old fashioned” oats and hay person, but also understand that sales and marketing sometimes exerts overwhelming pressure on what is good sound nutrition and common sense.
A: The addition of fat to the equine diet is just about the most researched topic in equine nutrition. Work has been done involving almost every age group and under almost every circumstance you can imagine. Universities like Virginia Tech, University of Kentucky and Texas A&M have done much of the research, but numerous others have done their share at exploring different aspects. The Equine Nutrition and Physiology Society Proceedings are full of fat research done over the last 20 years.
Unfortunately, most of the studies have been fairly short term, lasting 16 weeks or less. This does not answer the question of the long term effects of high fat diets. Kentucky Equine Research (KER) completed a study which involved feeding high fat diets for 15 months. Several parameters were monitored which would indicate whether it was harmful to keep them on the fat that long (we were particularly interested in liver damage). The only difference we saw was higher blood cholesterol but that in itself did not appear to affect performance in anyway. The equine digestive tract is designed to handle reasonable amounts of fat. Unlike ruminants, the small intestine of the horse comes before the fermentation vat. This gives the horse the excellent opportunity to get the full benefit of the fat in the diet before it hits the microbes (where high fat can be a problem). Not that it is not impossible to overwhelm the equine digestive tract with fat – I have seen problems when horses are fed excessive amounts of fat (particularly animal fat). But as long as a horse is eating well, performing well, looking healthy and acting sane, I do not have anything against adding fat in the diet.
Research is limited by the amount of money that can be put into it. I am afraid that only time will tell whether there really are long term problems with added fat in the equine diet, but so far things look pretty promising.