Combining ethological thinking and epidemiological knowledge to enhance the naturalness of organic livestock systems.

Organic livestock farming places strong emphasis on conditions that allow animals to exhibit behavioural needs. This involves the provision of a natural environment and, in particular, outdoor conditions and a reliance on natural forages. Such environments also allow animals to be effectively integrated into crop production. However, there are potential disease risks associated with these conditions, with control options being partly limited by restrictions on chemoprophylactic measures. Examples from dairy and poultry production demonstrate how a basic understanding of ethology and a knowledge of disease epidemiology can enhance the welfare of animals whilst satisfying the ecological objectives of organic farming. Existing epidemiological models and published data can be used to examine the potential ensuing health hazards and control possibilities and to suggest alternatives.