THE MILKNESS of the ASCANIAN FINE-FLEECED BREED of EWES and the MOLECULAR GENETIC MARKERS
Aim. Search for a relationship between genetic markers and the ewes' dairy productivity level. Methods. Immunogenetics, genetic and biochemical, biometric. Results. The dairy yield of the Ascanian FineFleeced breed of Tavrian Type ewes was determined, which averaged 44.2 kg. At the same time, ewes with one lamb had 36.7 kg, with twins - 52.3 kg. It was established that, according to the blood group systems, the distribution of antigens and phenogroup within groups of animals with different levels of dairy productivity basically does not have dynamically regular changes. With an increase in dairy level of animals, there is only a decrease in the proportion of antigens A (a), B (g) of the A and B systems of blood groups in the animal genotype and an increase in the concentration of anti-A (-). More significant changes were established at the transferrin locus, namely: an increase in the concentration of the TfA allele in the group with singles (from 0.182 to 0.350) and with twins (from 0.222 to 0.369), an increase in the concentration of TfC in the same direction. The proportion of the TfD allele, on the contrary, is dynamically reduced from class M¯ with singles (0.727) to M+ with twins (0.333). Animals with the rare TfE allele in the genotype had a low level of dairy productivity. It was also found that with an increase in the dairy ratio, the level of heterozygosity also increases. Conclusions. When determining the effect of the markers used in the study on the ewe's dairy production level, the Tf locus was the most interesting and informative. Changes in the concentrations of 6 alleles of this locus were dynamic. The increase in the concentration of the rare TfC type in the direction of species M¯ with individuals in M+ with twins can be an explanation of the phenomenon of increased viability and fitness of some genotypes with this gene. The low dairy production of animals with the TfE gene in the genotype could be one of the reasons for the elimination of this allele in the Tavrian sheep population. According to the Tf locus, heterozygous genotypes were more productive.