A recent study carried out by Houdijk et al (2005), used a rodent model to assess whether a reduction in protein scarcity during lactation resulted in a reduced degree of parasitism. Feeding high protein foods resulted in a reduced worm burden, but was confounded with increased food intake per se. Therefore, effects observed on parasitism may not necessarily have been associated with an increased protein supply, but with changes in the gut environment due to the increased food intake. Before this model can be used to assess the underlying immune responses, further work is needed to verify that the effects observed are indeed related to changes in nutrient supply. This experiment aimed to provide further evidence on the nutritional control of parasitism during lactation by manipulating nutrient demand. It was expected that the latter would not be associated with changes in food intake per se and results could therefore be used to exclude the influence of non-immunological changes in the gut environment as a contributing factor of reduced parasitism.