Nematode control in 'green' ruminant production systems.

Collectively, nematode parasites of domestic ruminants continue to pose the greatest disease problem in grazing livestock systems worldwide, despite the powerful and extensive chemotherapeutic arsenal available for their control. The widespread development of anthelmintic resistance, particularly in nematode parasites of small ruminants, and the trend towards non-chemical (ecological, organic, green) farming of livestock has provided an impetus for the research and development of alternative parasite control methods. This article provides a brief overview of the non-chemotherapeutic options for parasite control and how they might play a role either in organic farming or in other low-input farming systems.