Chelated Minerals

The term chelate comes from the Greek meaning crab’s claw. The term is applicable since the mineral is surrounded by a molecule which holds the mineral in a claw-like manner. Chelating and sequestering agents which occur as natural compounds in feedstuffs may increase or decrease mineral absorption and utilization. Commercially-produced chelated minerals may have greater bioavailability than non chelated forms of the same mineral, especially in nonruminant animals such as the chick and pig, because they are more soluble at the site of absorption. In ruminant animals, chelated minerals have been of less concern due to the rumen microbes and their involvement in digestion.

Currently, several minerals are available in chelated form. Among these are magnesium, copper, cobalt, iron, manganese and zinc. Under certain conditions ruminants have responded to mineral chelates, but it is not clear from the studies reported whether this response is due to the form of the mineral or simply to increased mineral consumption. Zinc-methionine may have an advantage in treatment of footrot and its prevention in problem herds, as well as improved immune response in cattle. However, there is limited research to support these conclusions. Copper availability may be low for ruminants in areas where molybdenum and sulfur are high. Providing copper in a form that does not interact with these antagonists would be advantageous, but it is not clear that copper chelates meet this objective.

While chelated minerals may have a special role under certain conditions and in future dairy cattle feeding programs, information presently available does not consistently show advantages for their inclusion in the diet. Also, some nutritionists find it more economical to add more of a nonchelated mineral rather than use a more bioavailable chelated mineral.

Feeding Dietary Cation-Anion Rations in the Prepartum Period

Dietary cation-anion balancing is a new concept that has received much attention in recent years as a nutritional tool for reducing the incidence of milk fever and perhaps retained placenta. Minerals considered in the balancing concept are sodium, potassium, sulfur and chlorine. The ration is fed for about 3 weeks prior to calving.