ASSOCIATION OF ALLELES FOR THE CLASS-I BOVINE LYMPHOCYTE ANTIGENS WITH CONFORMATION, SEMEN TRAITS, AND GROWTH-RATE OF YOUNG BULLS

The 279 Norwegian bulls that were performance tested during 1988 and 1989 were typed for bovine lymphocyte antigens of class I, and relationships with performance test results of these bulls were investigated. A single-trait animal model was used to estimate the gene substitution effects of bovine lymphocyte antigens on conformation as well as semen volume, density, and quality; a fixed linear model was also applied to the breeding values of growth rate. Allelic frequencies ranged from .2 to 28%; alleles w16 (28%), A2 (15%), A10(w50) (12%), and A8 (10%) were the most frequent. Allele A12(A30) was significantly associated with decreased semen density and decreased growth rare, and allele A10(w50) was significantly associated with increased growth rate. No antigen showed a significant association with conformation, semen density, or semen quality. Heterozygosity at the locus for bovine lymphocyte antigen of class I did not show significant advantage in any of the traits. The bovine lymphocyte antigens appeared to be potential markers for quantitative trait loci controlling semen density and growth rate; however, further research is necessary to confirm these findings.