2.2 Genetic Variation in Trace Element Metabolism

This paper reviews evidence showing that heredity is involved in the utilization of trace elements by animals. Underwood (1981) has stressed the importance of achieving dietary balance in the provision of minerals in animal nutrition and Howell (1983) has emphasized that although a small amount of a trace element may be essential for health a larger amount could be injurious. In these circumstances, information which can be used to meet the essential requirements for trace elements more precisely is likely to help in optimizing animal performance and avoiding risks to health and life. An understanding of the role of heredity in influencing trace element requirements is important in this context. Genetic variation in requirements also suggests the possibility that genetic solutions to trace element deficiency or toxicity problems may provide an alternative strategy to prophylaxis and other nutritional and management aids.