Genetic specificity of high milk productive Brown Swiss cows

Abstract

There were  studied the genetic characteristics of longevity cows of the Brown Swiss breed of the breeding reproducer of ZAO im. Michurin using immunogenetic monitoring. The research in the laboratory of zootechnologies of the Smolensk Research Institute of the Federal Research Center for Bast Fiber Crops was carried out in accordance with generally accepted methods. The duration of productive life of cows was, on average, 6 lactations with lifetime milk productivity of 27,000 kg of milk with a fat content of 3.88% and a protein content of 3.37%. When analyzing the milk productivity of cows carrying different EAB alleles, the highest indicators were found in longevity cows having the following alleles in the EAB genotype: P₁I^/, B₁I₁T₁A^/₂P^/, Y₂, Y₂G^/Y^/G^//₁, Q B₁G₂KY₂E^/₂F^/₂G^/O^/G^//₁ I₁Y₂E^/₂G^/I^/G^//₁, B₂O₃Y₂A^/₂E^/₃G^/P^/Q^/Y^/ and B₁I^/Q^/. The lifetime milk yield of cows with these markers was 28016 kg -33683 kg of milk, milk fat yield 1073.0 kg - 1339.1 kg, milk protein 694.7 kg - 1148.5 kg, with productive life duration of 9.2 - 11.3 years. Carriers of the EAB markers G₂O₂E^/₂I^/, O₂E^/₂G^//₁ and B₁I^/Q^/ inherited from Jersey bulls used in the improvement of Brown Swiss cattle were distinguished by a higher fat and protein content in milk – 3.92% and 3.41%, respectively, they were used in a herd of 8.2 – 9.8 years. The leaders of productive longevity with a lifetime milk yield of over 40,000 kg of milk and a life duration of more than 13 years were cows whose genotypes contained the EAB-alleles G₁O^/, I^/, I₁, O^/, P₁I^/, B₁I₁Q, B₁G₂KY₂E^/₂F^/₂G^/O^/G^//₁ and B₂O₃Y₂A^/₂E^/₃G^/P^/Q^/Y^/.