Trace minerals are essential to an animal for normal health and productivity. They act as the keys that assist in the utilisation of energy and protein within the body. As such they are important for normal growth, meat, wool and milk production, fertility and immunity. Trace minerals are required constantly but at certain times such during the growth of a young animal or during pregnancy and lactation or when experiencing increased stress for whatever reason, the animal’s demand can increase.
Deficiencies can present either as overt clinical disease or, more commonly, subclinically with less obvious signs but still significant productivity losses. If clinical disease is present this often the “tip of the iceberg” and many more animals are deficient and not showing obvious signs.
Deficiencies of selenium, cobalt and copper are common in ruminants in many parts of Australia. We will cover cobalt deficiency in the next section.
Copper is essential for connective tissue production such as bone and joint cartilage, hair and wool development including pigmentation, production of red blood cells and also for nervous system function. Animals can be deficient because they do not get enough from their diet, known as primary deficiency, or if there are interfering elements in the diet which reduce copper absorption. Elements such as molybdenum and sulphur for example, which are often included in fertilisers, can block absorption of copper.
Copper deficiency can be a problem on irrigated, lush green pasture, acidic, coastal sandy, granite soils and peaty swamp land, pasture fertilised with lime or molybdenum-based fertilizer. Copper is better absorbed when pasture dries off (summer) in comparison to spring pastures. Cattle are more susceptible to deficiency than sheep and some breeds e.g. Simmental and Charolais cattle have a higher copper requirement than others e.g. Angus cattle