Keywords: Micronutrients for grass, Trace elements, Micronutrients for ruminants, Copper, Cobalt, Selenium.
Trace elements for healthy stock; Zinc for growth and prosperity; improve human health by spreading Selenium on your farmland; enjoy the benefits of healthier, more productive stock with mineral licks. These are some of the marketing approaches taken to the selling of micronutrients to the livestock farming community. The messages may indeed be correct and the products that are sold may indeed be necessary and play a vital role in managing livestock systems. However, the objective of this paper is to rationalise the place of micronutrients in ruminant (grass) animal systems; steering a, hopefully, clear path to stating their importance, how problems might be diagnosed and the most appropriate means of solving deficiencies.
It is clear from the literature that deficiencies of micronutrients, particularly in their sub-clinical form where they are not visually apparent, can result in major reductions in the health and productive performance of livestock. Micronutrients are used mostly as the central elements of enzymes and co-enzymes in the biochemistry of ruminants. Thus, their deficiency often leads to sub-optimal growth and fertility.
Within the farming system, the aim should be to only use supplementation with micronutrients where it is necessary; that is, where an actual or likely deficiency has been diagnosed. Further, the supplement used should be cost effective and appropriate to the farming system in question.
Gaps in knowledge still remain, the most obvious being the use and levels of micronutrients that are typical in manures and the use of these in animal systems. For any reader interested in delving further into micronutrients and livestock farming, Underwood (1971) and Underwood and Suttle (1999) are recommended.
George E J Fisher, PhD., Kemira GrowHow UK Ltd, Ince, Cheshire, UK.
23 pages, 1 Figure, 10 Tables, 28 References.