An ovine lymphocyte antigen is associated with reduced faecal egg counts in four-month-old lambs following natural, predominantly Ostertagia circumcincta infection

Ten lymphocyte antigens were defined in a flock of Scottish Blackface sheep known to be naturally exposed to infection with Ostertagia circumcincta. Population and family studies suggested that the 10 antigens were products of class I loci, Antigen G13br was in linkage disequilibrium with allele g2 at the DRB1 locus. The g2 allele has previously been associated with reduced faecal egg counts in a different crop of lambs from the same farm, In this study antigen G13br was also associated with a reduction in faecal egg counts. The results provide partial confirmation of the role of the major histocompatibility complex in resistance to natural, predominantly O. circumcincta infection. Copyright (C) 1996 Australian Society for Parasitology.