Ruminant livestock have a special role in organic agriculture. They provide an essential component of a balanced crop rotation system with grass/clover leys and arable cropping. Consequently, the less intensive systems of beef, sheep and dairy production have led the development of organic livestock production in most European countries (Foster and Lampkin, 1998). Whilst organic beef production was initially far more common than organic dairy production in the UK, the latter has recently gained more importance, as marketing outlets and consumer demand for organic milk have developed.