HLA-C and viral load: This chromosome is known to have two subregions (classes IIa and IIb) of the bovine leukocyte antigen (BoLA), also called bovine major histocompatibility complex (MHC), which is determinant in the development of acquired immune responses to diverse parasitic and viral diseases (Ellis and Ballingall, 1999; Takeshima and Aida, 2006).