DISTRIBUTION OF ALLELE FREQUENCIES IMPORTANT TO MILK PRODUCTION TRAITS IN LITHUANIAN BLACK & WHITE AND LITHUANIAN RED CATTLE

Summary. Lithuanian Black & White (LBW) and Lithuanian Red (LR) cattle belonging to the modern breeds form 99% of the total Lithuanian cattle population. These breeds have been intensively selected for milk production during the last 50 years. Associations were analysed between polymorphisms localized in six different polymorphic sites: four polymorphisms in the 5'-noncoding region of GHR gene: RFLP-AluI, -AccI and -Fnu4HI (located within the 1,206-bp LINE-1 element) and -Sau96I (located within the P1 promoter); one polymorphic site located in exon V of GH gene - RFLP-AluI, and RsaI polymorphic site located in exon 3 of the bovine PRL gene, including 52 LBW and 136 LR cattle. Genomes were identificated by the PCR-RFLP method. The relative frequencies of alleles were determined for Lithuanian Black & White and Lithuanian Red cattle: GHR(Alu+) and GHR(Alu-) alleles - 0.45, 0.55 and 0.64, 0.36; GHR(Acc+) and GHR(Acc-) alleles - 0.62, 0.38 and 0.53, 0.47; GHR (Fnu4H+) and GHR (Fnu4H-) alleles - 0.87, 0.13 and 0.90, 0.10; GHR(Sau 96+) allele - 1.00 and 1.00, GHR(Sau 96-) allele were not found in both breeds; GHL and GHV alleles - 0.70, 0.30 and 0.77, 0.23; PRLA and PRLB alleles - 0.79, 0.21 and 0.87, 0.13, respectively. Except for GHR-Fnu4HI and GH-AluI loci, significant differences between the allele