International approaches to the concept of integrated control of nematode parasites of livestock.

Livestock production systems throughout the world are under severe and sustained pressures. These are diverse and multi-factorial, ranging from the need to redress the oversupply of livestock commodities from the protected industries of the industrialised world, meeting animal welfare expectations, attempts to ease animal-induced land degradation and pollution, and competition with alternative products. As a consequence, funding for research to the ruminant livestock industries has been contracting universally. This applies particularly to research on those diseases of grazing livestock that are not zoonotic, threats to trade, or major "killer" diseases. Gastrointestinal helminths fall outside these priorities. The last decade has witnessed a major contraction throughout the world in the number of research centres and staff involved in applied veterinary parasitology research. This coincides with a time when these livestock industries need the most help. Resistance to anthelmintic drugs amongst the major nematode parasites of sheep and goats has now reached alarming proportions throughout the world and threatens the future viability of continued small ruminant production in many countries. Anthelmintic resistance is also increasing in the important nematode parasites of cattle. Also, this time coincides with the apparent reduction in the discovery and development of entirely new anthelmintic products by the pharmaceutical industry. As a consequence, those remaining researchers and extension personnel who have the responsibility of providing support to the ruminant livestock industry, are showing innovation and lateral thinking in ways to combat the perennial problem of internal parasites in grazing livestock. There are a number of excellent examples of parasite-control schemes, which do not rely entirely on anthelmintic treatment. These are now being supplemented with some exciting novel approaches to dealing with particularly pressing parasite problems. Also there is a move towards the development of true integrated approaches in the control of nematode parasites of livestock, which employ several of these methods when appropriate. This proves that as far as worm control in livestock is concerned, the old adage "necessity is the mother of invention", holds true.