Assessment of bulls by capa-casein in the conditions of the Udmurt Republic

Abstract

In the article the analysis of bulls-producers used in the republic, depending on polymorphism on k-casein is carried out and the influence of genetic resources on the level of milk productivity, quality of milk and its dampness is determined. It has been revealed that 56 % of bulls in the republic have AA-genotype, 40 % have AB and only 4 % have BB-genotype. The highest yield for 305 days of lactation in cows with BB- and AB-genotypes 6018 and 5985 kg, respectively. Protein content in BB-cow milk was 3.15 %, which is 0.14 % higher in comparison with AA-cows (P ≥ 0.95) and AA-cows – 0.06 % higher. More than a half of all milk examined in the group of cows with BB- and AB-genotype on k-casein (90 and 85 %, respectively) had on rennet and fermentation sample I and II class. In the Udmurt Republic β-asein contains only 26 %, which also affects the quality and yield of finished products, in particular, rennet cheeses.