The effect of including immune competence in Merino sheep breeding programs

The effect of including general immune competence (IC) as a novel trait in a fibre production (FP) and a dual purpose selection (DP) index was investigated. Two levels of economic values were assumed for IC and the sensitivity of index responses to these were tested. The results showed that the addition of IC to a selection index requires careful consideration in order to achieve the envisaged improvements in health and welfare outcomes expected while addressing primary production objectives.