Variability of indicators of dairy productivity of cows of different genealogical lines

Abstract

As a result of targeted selection and mating, a highly productive herd was formed in the OJSC Povadino Breeding Farm in the Moscow Region. However, the breeders of the farm do not stop at the achieved level of productivity of cows and consider diff erent breeding techniques in order to consolidate the results obtained. Evaluation of the productivity of fi rst-calf cows is an important element in the selection of highly productive cows. The purpose of the research was to study the variability of indicators of dairy productivity of cows of diff erent genealogical lines. The coefficient of variability of trait of dairy productivity is considered as one of the criteria for assessing the breeding value of cows during selection. The Holstein sires of Montwik Chieftain 95679, Refl ection Sovereign 198998, Wes Back Ideal 1013415, Sealing Trijun Rocket 252803 lines represent the important breeding value in terms of milk productivity. With line-group mating, the highest coeffi cient of milk yield variability in fi rst-calf cows was observed in progeny of the line Montwick Chieftain 95679. According to the content of the mass fraction of protein in milk, it was high in cows of the line Sealing Trijun Rocket 252803. With lines crossbreeding, milk yield increased in the progeny of all genealogical lines, but the coeffi cient of variability of milk yield did not change and remained within the same limits as for the fi rst lactation. However, the variability in the mass fraction of fat in cows of the lines crossbreeding Refl ection Sovereign 198998 and Sealing Trijun Rocket 252803 increased. The coeffi cient of variability of the mass fraction of fat and the mass fraction of protein at the crossbreeding of the genealogical lines remained within the same limits as with line-group breeding. Thus, in further breeding work it is possible to improve the herd using different selection mating, taking into account the coefficients of variability of traits of dairy productivity.