Horse Nutrition: Chelated Minerals

The level of chelated minerals in livestock feeding is typically added at 25-30% of the total mineral in a feed. If the chelated mineral enhances absorption why not use 100% of the mineral from chelates? Price becomes a factor as chelated minerals are expensive.

Chelated mineral products have been available for many years and more recently have seen increased usage in horse feeds. What is a chelated mineral? In very simple terms, a chelated mineral is a mineral such as copper, zinc, manganese, cobalt or iron (there are others) that is bonded to "small proteins", peptides or amino acids.

The process of chelating improves the absorption of the mineral from the digestive tract. How this improvement is actually achieved is unknown at this time but it has been suggested that the chelated mineral is more soluble and can cross the intestinal wall more easily, (Rompala & Halley, 1995).

Jackson (1991) reported the differences in absorption of chelated trace minerals in comparison to the inorganic form. This information is summarized in Table 1.



Table 1. Relative availability (%) of chelated minerals compared to typical inorganic mineral sources (Jackson, 1991).

Form of Mineral	Copper	Zinc	Manganese
Inorganic	100	100	100
Chelated	140	125	121

The benefits of using chelated minerals for livestock has received a great deal of research interest. The areas that have been studied are reproduction, health, soundness and growth. Research into chelated minerals for horses has focused on the broodmare and the young growing horse.

Much of the research on feeding chelated minerals to horses has shown varied results. Researchers in Florida found that mares receiving trace mineral supplementation in a combined inorganic/chelated product had a tendency for a reduction in the number of cycles bred and in the number of services per mare. However, there was no effect in conception rate, (Ott & Asquith, 1994). Other researchers have suggested improvements in reproductive performance in barren or open mares by reducing time to first cycle or reducing early embryonic loss when chelates were fed. However these studies have included other management practices which may have affected the improvement in reproductive efficiency, (Ley et al, 1990, Roble & Farfa, 1987).

In the growing horse limited research has been published. In 1995 Ott & Johnson reported that using chelated minerals in diets for yearling did not improve weight gain or wither height. However that study did show some very interesting results related to hoof growth. The addition of a chelated mineral product (which supplied a portion of copper, zinc and manganese as chelates) resulted in an improved hoof growth for the yearlings receiving that diet. There was no increase in strength of the hoof wall but growth was enhanced. Similar results have been reported with dairy cattle fed chelated products.

The other area where chelates have received some attention is related to the immune system. It is well known that providing adequate levels of trace minerals is required for proper immune function. Because of the increased availability of chelated products it is thought that their use will enhance immune function, (Vandergrift, 1993).

Chelates have been recommended for enhanced reproduction, growth, soundness and immune function. While the addition of a chelated product to a feeding program will improve the availability of the mineral to the horse it is unclear how this improved availability will affect production. In situations where it is critical that the horse's requirements for a particular mineral or minerals be met, the addition of a chelated product may be beneficial. It is important for horse owners to realize that while the use of a chelated mineral product may provide a benefit it should only be used as part of a good farm management program not a replacement.

Dr. Bob Coleman was formerly an Equine Nutritionist and Horse Specialist with Alberta Agriculture Food and Rural Development. Dr. Coleman is currently the Equine Extension Specialist with the Department of Animal Sciences at the University of Kentucky.