Associations between the bovine major histocompatibility complex (BoLA) and milk production in Icelandic dairy cattle.

Associations between BoLA type and milk production were investigated using information from 80 Icelandic cattle from four dairy farms in Iceland. The specificity w6 reduced milk, fat and protein yield. Although w6 has been shown to be associated with increased susceptibility to mastitis, there is no evidence to suggest that the reduced yields here were due to mastitis. The association may be due to increased disease susceptibility or due to a direct effect of BoLA Class I antigens.