Detection of candidate regions affecting bovine IgM natural antibodies in milk

Two genomic regions were found to be associated with IgM antibody titers in milk binding lipoteichoic acid (LTA); one on chromosome 17 and the other on chromosome 21. Phenotypes were measured by ELISA and genotypes consisted of imputed 777k SNP. Single SNP analyses were run using an animal model to retrieve significant SNP. In BTA21, a gene for the heavy chains of immunoglobulins, IGHV is proposed as a candidate gene as was true for VPREB3 in BTA17 related to B-cell maturation. These findings provide a further step in better understanding the genetic background of natural antibodies (NAbs), that may be relevant for relevant for the estimation of dairy cattle health. Keywords: dairy cattle, natural antibodies, genome-wide association