Abstract

Sequence polymorphisms of the BoLA-DRB3 gene were investigated in 1058 cows belonging to seven dairy Gyr herds. A total of 37 alleles were identified, 15 of them described for the first time in Zebu breeds. A highly significant association (P<0.02) was observed between allele *54 and a decrease (-26.1 kg) in milk protein yield. This same allele was also significantly associated (P<0.05) with lower (-26.07 kg) milk fat yield. Indications of associations (P<0.10) were found for alleles *3 and *31, which promoted increases of 0.56 and 0.46 units in the somatic cell score, respectively. The highly significant association of allele *54 with lower protein yield suggests the possible use of this allele in marker-assisted selection programs.

C. S Nascimento, A. LS Azevedo, M. A Machado, M. L Martinez, M. VGB Silva, M. FM Guimaraes, A. L Campos, R. L Teodoro, R. S Verneque, S. EF Guimaraes, D. AA Oliveira

Proceedings of the World Congress on Genetics Applied to Livestock Production, Volume , , 22.52, 2006