Seasonal infections and nutritional status.

The purpose of the present paper is fourfold: first to draw attention to the enormous impact which seasonal infections by nematodes can have on the nutritional status and growth of ruminants, despite regular dosing with anthelmintic; second, to suggest a primary role of larval challenge as a source of those nutrient losses; third, to create awareness of the delays which may occur between seasonal infection and nutritional impact; fourth, to suggest new approaches to the reduction of parasite-induced malnutrition in infections, both seasonal and aseasonal, in animals and man.