GENETIC POLYMORPHISM AT THE K-CASEIN LOCUS IN A DAIRY HERD OF ROMANIAN SPOTTED AND BROWN OF MARAMURES BREEDS

The objective of the present study was focused on possibilities to estimate the allele and genotype frequencies of β-lactoglobulin (BLG) gene polymorphisms in dairy cattle belonging to two different genetic groups from the Research and Development Station for Bovine Raising Arad in order to have breeding programs that target an increase in the frequency of the B allele in the dairy cattle population. Genotyping was performed on 20 Romanian Spotted and 18 Brown of Maramures cattle.In order to differentiate the favorable genotype for superior composition and higher cheese yield, we used simple DNA extraction method from fresh blood and techniques based on DNA analysis, which include polymerase chain reaction and restriction fragment length polymorphisms (PCR-RFLP) methods. Employing these techniques we were able to determine the (BLG) genotype of all individuals in a given population under selection, regardless of sex, age or physiological stage. As a result, it is now possible to include information on milk protein genotypes into marker assisted selection programs and consequently improve response to selection.