Modifying procedures to assess immune competence in mature boars

Abstract

Survival of progeny through to slaughter age is a key driver directly impacting on profitability and animal welfare within the Australian Pork Industry. Vaccinations against diseases causing mortality, such as Actinobacillus pleuropneumoniae (APP), are not always effective, suggesting a proportion of animals are responding poorly to vaccination. Immune responsiveness, the body's ability to respond to foreign antigens and render it harmless, involves a complex network of factors (Mallard et al. 1992). Since it is not possible to identify all of the genes that contribute to enhanced immune competence, an alternative strategy is to consider immune competence as a quantitative trait with a measurable phenotype (Hine et al. 2012). Procedures using test antigens (Mallard et al. 1992; Wilkie and Mallard 1999) have been developed to assess immune competence phenotype in pigs, combining measures of an animal's ability to mount both an antibody mediated immune response (AMIR) and cell mediated immune response (CMIR). This study tested the hypothesis that similar procedures, using commercial vaccines rather than test antigens to induce measurable responses, could be used to assess immune competence in mature boars. Use of commercial vaccines removes the requirement for test antigens to be registered for use in food-producing animals.