Mineral Supplementation For Ruminants

This article provides a brief overview of a very important but complex subject. The aim is to give the ruminant producer a broad framework for decision-making to optimise management.

- Sjoerd ten Cate

Several minerals are required for the normal functioning of essentially all metabolic processes in ruminants. Dietary deficiencies or excesses of certain minerals can result in substantial economic losses in animal productivity. A sufficient supply of minerals is essential to optimise milk production, growth, fertility, health and immunity of ruminants.

Macro- and microminerals

In animals, seven elements, namely calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K), sodium (Na), chlorine (Cl) and sulphur (S), must be present in the diet in fairly large amounts (grams to tens of grams per day) and are termed essential macrominerals.

Other elements, termed essential microminerals or trace minerals, are required in much smaller amounts (milligrams to micrograms per day). These include iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), cobalt (Co), selenium (Se), iodine (I) and molybdenum (Mo).

Keep in mind, though, that the higher the production and reproductive status of an animal, the more of these essential minerals are required to optimise the increasingly harder working metabolic processes. For example, an average weight dairy cow needs approximately 51g of Ca to produce 9kg of milk, compared to 162g of Ca to produce 41kg of milk. Lactation is hard work, but so is growth. A 30kg growing lamb in the feedlot needs around 24mg of Zn per day to gain 200g in weight, compared to 40mg of Zn to gain 400g.

Role of soil conditions