Estimation of dairy productivity of Kholmogorsky cows with allel variants of prolactin and somatotropin genes

Abstract

The interrelation of allelic variants of prolactin and somatotropin genes with indicators of milk productivity of cows of the Kholmogory breed for the 1st and 3rd lactation was studied. The highest milk yield (5040 and 5836 kg) amount of milk fat (194,5 and 224,1 kg) and milk protein (163,8 and 189,1 kg) are observed in the group with the PRL AA genotype in first-calf heifers as well as in full-age cows. In terms of the mass fraction of fat and protein in milk the 3rd lactation cows with the PRL genotype BB significantly exceeded the other groups of animals by 0,13-0,15% (P <0,001) and 0,05% (P <0,05), respectively. According to the somatotropin gene, the highest level of milk productivity was revealed in animals with the GH LL genotype, with a significant advantage over full-age cows GH VL and GH VV in milk yield by 280 kg (P <0,001) and 509 kg (P <0,001), by the amount of milk fat by 9,1 kg (P <0,001) and 18,5 kg (P <0,01), by the amount of milk protein per 7,9 kg (P <0,01) and 14,8 kg (P <0,01). The highest butterfat and protein-milk content belongs to animals with the GH VV genotype that are 3,90% and 3,26%. The obtained data indicated a higher level of milk productivity in cows with the PRL AA and GH LL genotypes, but the best fat and milk content was noted in cows with the B allele of the PRL gene and the V allele of the GH gene in their genotype.