October 2011 - The availability of minerals in rations for horses
There is a lot of discussion about the chemical form of minerals (ie. Magnesium, Phosphorus, Copper, Zinc, Selenium etc.) that are added to horse rations. When we provide extra minerals in concentrates or in a mineral supplement, this is traditionally in the form of inorganic salts.
Minerals can, however, also be bound to an organic molecule, such as an amino acid. They can also be fed with yeast or fungi that have incorporated the minerals during their growth. Minerals bound to organic molecules are usually called chelated minerals.
If we search the Internet for "chelated minerals for horses", we get many hits. Most articles are written as part of the marketing of products containing chelated minerals. It is often claimed that chelated minerals in a given product are taken up by the horse in a much better way than is the case with the inorganic forms. Products with chelated minerals are generally more expensive than similar products with inorganic minerals.
The picture is somewhat different in literature reporting experiments on the absorption of inorganic and chelated minerals. The official American standard of nutrition of horses (Nutrient Requirements of Horses, NRC 2007) comments on how well minerals are absorbed on the basis of published results of digestibility trials.
The findings are not always as clear as claimed in advertisements for chelated minerals
Indeed, some minerals have a somewhat better absorption in chelated rather than in inorganic form, others have a similar, or even lower absorption.
The main message in NRC 2007 is that there are no major differences between inorganic and chelated minerals in respect to sustaining adequate minerals nutrition. When calculating the need for individual minerals, NRC takes into account how well the mineral is absorbed. For a mineral where 50% of the content of the feed is absorbed, NRC puts the horse's daily requirements at twice the amount the body needs to absorb from the intestinal tract. Thus, when using mineral requirements as published by the NRC, PC-Horse also takes into account how well the different minerals in the total ration will be absorbed by the horse.
Your PC-Horse program calculates the minerals needed by all types of horse according to NRC 2007 standards. In respect to minerals for horse nutrition, we consider these standards to be the very best in the world.
As more scientific evidence becomes available on the absorption and utilization of various chemical forms of minerals, we will incorporate it in the calculation engine of the PC-Horse program, enabling us to provide ever better nutritional advice to horse owners.
This article was originally written by Dr. Day Austbø.
Copyright: PC-Horse International - Norway 2012.
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