DOMINANCE OF ALLELES IN HETEROZYGOUS BETA-LACTOGLOBULIN GENOTYPES OF THE CATTLE

4355 milk samples of 1991 Fleckvieh and 1453 Braunvieh cows were analyzed for beta-lactoglobulin content and yield to determine the expression of the beta-lactoglobulin alleles A and B in heterozygous and homozygous genotypes. Allel A significantly showed a stranger expression than allele B in all cases, whereby the differences in heterozygotes were greater than in homozygotes. A genetic model of allelic effect was defined which contains two dominance effects of heterozygous genotypes. Significant dominance effects of alleles had values of up to 10 %. Antagonistic signs of the dominance of the alleles led to relatively, small total dominance of the heterozygous genotypes. Seasonal dominance and dominance during the lactation period was estimated and continous positively dominance of the allele A and negatively dominance of the allele B occured. It is presumed that the antagonistic dominance effects of alleles of the beta-lactoglobulin locus is a general appearance.