Ecology/Physiology Workgroup Nematode Parasites in Small Ruminant Grazing Research: Changing Perspectives

Grazed forages are an economical feed source and are a critical component to profitable sheep and goat production in the US, particularly in the South, where year-round pasture growth is possible. As with all grazing livestock, the profitability of pasture-based small ruminant production is intimately tied with controlling infection from gastrointestinal nematodes (GIN). These parasites cause economic losses through decreased production, cost of prophylaxis and treatment, and death of infected animals (Miller et al., 2005). For small ruminants world-wide, more money is spent on prevention of diseases from internal parasites than from all other diseases combined (Bath and de Wet, 2000). In the southern US, infection with GIN is the primary constraint to profitable production and could eventually threaten viability of the small ruminant industry in this region. Addressing this problem is important for both parasitologists and forage/pasture researchers. Therefore, this paper will focus primarily on the effects of parasitic infection in small ruminants, novel methods for controlling parasitic nematodes in sheep and goats, interaction of GIN and forages/pastures for small ruminant production, and the need for increased research in this area.