The periparturient relaxation (PPR) in acquired immunity in ewes has been ascribed to various factors, including poor nutrition (Barger, 1993). Clinically, the faecal egg count (FEC) may increase during PPR when the ewe is continuously infected with gastrointestinal parasites. As such, the periparturient ewe plays an important role in the epidemiology of parasitic infections. The nutritional basis of PPR probably includes metabolizable protein (MP), since host's responses, in terms of immunity and resilience, are highly proteinaceous by nature. We propose that the PPR directly results from less MP being available to maintain acquired immunity and resilience, since an increasing amount of MP is directed to bodily functions with higher priority (reproduction). It is hypothesized that the increased FEC in the parasitized periparturient ewe reduces if her MP-intake exceeds her assumed MP-requirement (AFRC, 1993).