Characteristics of the families of the herd of the Sychevka breed by productive and genetic indicators

Abstract

An analysis of the genetic structure using marker alleles of the EAB locus and an assessment of the productive qualities of the families of cows of the Sychevka breed of the pedigree farm KP "Rybkovskoe" of the Smolensk region is presented. In the genotypes of representatives of families with a frequency of more than 5%, there are EAB alleles of the Holstein breed: Y₁A`<sub>1</sub>, G<sub>2</sub>Y<sub>2</sub>E`₁Q`, O<sub>2</sub>A`₂J`<sub>2</sub>K`O`, B<sub>2</sub>O<sub>1</sub>, and the Sychevka breed: O<sub>1</sub>I`Q`, b, O<sub>1</sub>Y<sub>2</sub>E`₃G`G``, which indicates the presence of hereditary material of both breeds. The average milk yield for maximum lactation in cows of the families was 5624kg of milk, with a fat content of 3.91%, protein 3.28%. In the best cows of the families, milk productivity reached 9651kg of milk, 3.71% fat, 3.28% protein for maximum lactation. Thirty percent of descendants from the families of Laskovaya 7114 and Kladi 8080 have a milk yield of over 6000 kg, with a fat content in milk of 3.82% and higher, and protein - over 3.35%. Milk yield in cows, on average in the group by the third lactation compared to the first increases by 970 kg of milk or 22%, which is largely due to the milking of animals in the process of their use. The greatest increase (41%) in milk yield to full-age lactation is observed in animals with the alleles E`₃G`G`` (+1681kg) and B<sub>1</sub>G<sub>3</sub>O<sub>1</sub>T<sub>1</sub>A`₁B`E`₃F`<sub>2</sub>Q` (+1706kg). Cows with the EAB allele B₁G₂O₁ are different by an increased (by 40%) period of productive use, and, as a result, lifetime milk yield, they are 42% higher than the average for families. Cows with the marker allele P₁QA`<sub>1</sub>J`₂E`<sub>1</sub>I` have lifetime milk yield indicators 69.5% higher than the average for families.