RESUMO
The purpose of this investigation was to establish parameters for the evaluation of immune competence in different swine breeds. Cellular and humoral immune reactivity against keyhole limpet haemocyanin (KLH) was analysed using the lymphocyte stimulation test (LST), a skin allergy test and the IgG response. Various characteristics of the KLH-specific immune response were studied in 988 sows of four breeds. KLH-specific immune responses showed considerable variability. The applied statistical model explained 63 to 73 per cent of this variation. Genetic influences, expressed as the heritability estimate, were rather high for the IgG response (0.33), as well as for the skin reaction (0.26) and the LST (0.41-0.45). A positive correlation between the various immune parameters was found. Selective breeding for immune responsiveness seems to be feasible, but selection for cellular as well as humoral immune reactivity also seems to be possible with KLH as the antigen.