Nutrition-parasite interactions in goats: Is immunoregulation involved in the control of gastrointestinal nematodes?

Compared to sheep, goats seem to develop a low immune response against the parasitic nematodes of the gastrointestinal tract. Nevertheless, some variability in the host response has been observed either at the individual level or depending on internal (genetic) or external (physiological status, nutrition) factors suggesting the possibility to exploit and manipulate this response. There is good evidence from field studies to suggest that a better plane of nutrition might contribute to improve goat resilience. However, the effects on immunoregulation and host resistance remain less clear. Due to their peculiarities in feeding behaviour ('intermediate browser'), goats represent a valuable model to explore the relationships between the three possible strategies to control nematode infection through nutrition: (i) by increasing the immune response; (ii) by avoiding the infective larvae; and (iii) by selecting plants with direct anthelmintic properties (self medication). © 2007 The Authors.