The post-challenge mean PCV of 7 low (group A) and seven high (group B) FEC phenotypes after H. contortus challenge infection, compared to seven animals (group D2) that remained naive throughout both escalating and challenge infections. SEMs are shown only on the extremes for clarity (For further details see Chiejina et al. [14]). Significant reductions in PCV occurred only in the high FEC phenotype but no cases of overt anaemia were observed in any of the goats.