Dietary protein supplies the body with amino acids, which the cells can reassemble to form body proteins specific to the tissue the body needs (bones, skin, muscle, etc.). When only one source of protein is fed, such as one type of grass, this is considered to be “poor-quality protein,” meaning there is not enough amino acid variety for the cells to combine into useful body proteins. Those amino acids that the cells can’t use (the left-overs) will be destroyed by the liver, potentially leading to the formation of glucose.
Elevated glucose leads to insulin secretion, which can be problematic for the insulin resistant or cushingoid horse.
By feeding several protein sources (e.g., different grasses, legumes and grain by-products), the amino acid pool will be improved, allowing your horse to produce the body proteins he needs.
Juliet M. Getty, PhD, is an internationally respected, independent equine nutritionist who believes that optimizing horse health comes from understanding how the horse’s physiology and instincts determine the correct feeding and nutrition practices. She is available for private consultations and speaking engagements. Getty provides a world of useful information for the horse person at www.gettyequinenutrition.com. Sign up for her informative, free monthly newsletter, browse her library of reference articles, search her nutrition forum, and purchase recordings of her educational teleseminars. And for the growing community of horse owners and managers who allow their horses free-choice forage feeding, Getty has set up a special forum as a place for support, celebrations, congratulations and idea sharing at jmgetty.blogspot.com. Reach Getty directly at firstname.lastname@example.org.