Genetic resistance to helminths: a possible relationship between haemoglobin type and the immune responses of sheep to non-parasitic antigens.

The results of some preliminary studies on a possible association between haemoglobin type and the antibody responses of sheep to a variety of non-parasitic antigens are described. Sheep with haemoglobin AA showed a significantly better response to human serum albumin than animals of the same breed with haemoglobin BB. There was also suggestive evidence of a better response by haemoglobin AA types to rabbit red cells and horse gamma globulin. These results indicate that the greater resistance of these sheep to gastrointestinal nematodes is reflection of their superior immunological competence.