Investigations in farm animals of associations between MHC system disease resistance and fertility

Abstract

Investigations of associations between the major histocompatibility complex (MHC) of cattle, horses and pigs and disease resistance and/or fertility are reviewed. Statistical models for analysing associations between the MHC and any trait are discussed. A model which considers all alleles simultaneously and provides estimates of allelic effects which are independent of allelic frequencies in the investigated populations is recommended. With this model it is possible to rank the alleles and compare this ranking among populations. Finally, data on the cattle MHC and resistance to respiratory diseases are analysed using the latter model. No genotypic or allelic effect of MHC on this particular disease complex could be demonstrated.