Chelated Minerals Enhance Nutrient Bioavailability
Chelation…bioavailable…proteinates…digestibility…organic minerals. What do these words mean? How do they relate to a horse’s health and performance? And, more important in some horse owners’ eyes, why do the big words on the feed tag mean a slightly higher cost for the feed?
Top-grade horse feeds supply the vitamins and minerals needed by horses to support growth, tissue maintenance, nerve function, and general health. Chelation (key-LAY-shun) is the chemical process by which a mineral (iron, cobalt, copper, zinc, manganese) is combined with a mixture of amino acids and peptides. The resulting substances are known as chelates. Another descriptive term, proteinates, refers to the amino acid bond. These chelated minerals are thought to be more digestible than nonchelated forms. In other words, chelation makes the minerals more bioavailable (able to be absorbed and used for bodily functions), chiefly by shielding them from the effects of other dietary elements in the animal’s digestive tract. Proteinates or chelates are described as organic minerals in contrast to inorganic minerals, those that are not bound to amino acids.
Horses and other grazing animals pick up much of their mineral requirement by ingesting a mixture of grasses and other plants as well as the small amount of soil that clings to leaves and roots. In a natural setting where grazers wander over a broad area, each animal encounters a smorgasbord of vegetation. Today’s horses, if they are turned out at all, are usually confined to relatively small fields with a restricted variety of grasses or legumes. Often the farmland has seen decades of grazing or cultivation, and its mineral stores may be seriously depleted. Couple these facts with the heavy demands of growth, training, and performance, and it becomes obvious that some type of mineral supplementation may be necessary for horses to grow and perform to their full potential.
Most minerals occur in several forms that can be mixed into feed. For example, feed manufacturers can choose from at least six forms of manganese. What makes one more desirable than another? Two factors, digestibility and cost, are generally taken into consideration. As might be expected, the most easily digestible mineral forms (the chelates or proteinates) are also those with the highest cost.
What about just adding a larger proportion of a less effective but cheaper mineral? That sounds like a way to keep prices within bounds, but studies have shown drawbacks to this approach. Absorption from the digestive tract does not increase significantly at higher inclusion levels, and in some cases a large intake of one mineral seems to block digestibility of another mineral. Using chelated minerals for some portion (about 25%) of the total requirement seems to be a workable compromise, producing a feed with an easily digestible mineral component coupled with only a slight price increase.
A number of studies with rats, fish, pigs, chickens, and cattle have noted improvements in reproduction, immunity, hoof quality, milk production, and growth rate as well as lower fecal excretion when diets contained organic minerals, indicating the organic forms were absorbed and retained at a high rate. Fewer studies have been conducted with horses, but equine research has indicated organic minerals could be expected to enhance immune function due to better bioavailability. In one study, supplementation with copper proteinates was beneficial to horses with developmental orthopedic disease, while inorganic copper sulfate at comparable levels did not lead to similar improvements.
Other equine research projects have linked chelated minerals to a reduction in early embryonic death rate, increased number of eggs produced per reproductive cycle, and an improvement in foaling rate.
Studies have shown that intensely exercised horses have an increased requirement for some minerals, and a ration containing chelated minerals will benefit horses in the top levels of equine sport. These athletes need a steady, reliable source of minerals for energy metabolism, tissue maintenance, and a healthy and resilient immune system. Organic minerals are an especially important choice for the rations of young growing horses. Correct amounts and ratios of many nutrients are essential for the development of bones, muscles, and nerves, and the use of organic minerals can help to ensure proper mineral balance and absorption.