Characteristics of the genetic structure of bulls of lebedinian breed by Beta (CSN2) - and Capa Casein genes (CSN3)
The Conservation of genetic resources in animal husbandry is a necessity arising from the possibilities and reality of the diversity of the gene pool available in the country, which determines the productive and adaptive capabilities of individual breeds of cattle. Aboriginal breeds are carriers of unique genes and gene complexes, which cannot be restored if they disappear. Marker-asissted selection is one of the current areas of improvement of dairy cattle productivity. It allows the selection
... llows the selection of parental forms at the genetic level. An important issue in the selection of dairy cattle today is the study of the relationship between hereditary factors that determine the types of proteins in milk. Genetic variants of beta-casein significantly affect on human health, kappa-casein is associated with the quality of raw milk and cheese making properties. The aim of the research was to study the available sperm production of Lebedinian bulls by beta- (CSN2) and kappacasein (CSN3) genes. The material for research was the sperm of bulls of Lebedinian breed cattle. Determination of beta- and kappa-casein gene polymorphism was performed by PCR-RFLP method in the laboratory of the Institute of Animal Husbandry of NAAS. Analysis of the genealogical structure showed that 12 bulls-producers belong to 8 lines. Of the 12 bulls, 5 are purebred Lebedinian, 7 are crossbreeds with the swiss breed. Among those studied for the complex genotype (CSN2- (CSN3), one bull had the desired genotype A2A2BB, another bulls had genotypes A2A2AB; A1A2BB; A1A2AB; A1A1AA. Five bulls have the A1A2AA genotype and two bulls have the A1A1AB genotype. The high frequency of the A2 allele of beta-casein (46%) and the B allele of kappa-casein (33%) was observed in sires of Lebedinian breed. To create micropopulations with the desired complex A2A2 / BB genotype, sires are recommended in which the frequency of alleles of beta-casein A2 and kappacasein B satisfies the requirements. Key words: sire, beta-casein, kappa-casein, genotype, allele, frequency, haploid.