Influence of the method of breeding daughters on breeding qualities of bulls

Abstract

The analysis of breeding value was carried out by 24 sire with a large number of daughters (more than 40), daughters were lactated in 22 herds in the Russian Federation. The breeding value of bulls is influenced by the method of breeding their daughters, and their distribution according to the level of breeding value. Most first-calves obtained by the cross-line method (over 90%), the average breeding value of the bull is determined by the level of breeding value of crossed daughters. Most of the bulls of a daughter, regardless of the method of their elimination, have the same orientation in assessments. It was revealed that the crossed daughters of Kazbek concede 4 kg, while the intra-linear ones outweigh 47 kg of milk, and Olympus - on the contrary +2 and -107 kg of milk, respectively. Daughters of bulls, deduced by different methods, are divided into three categories according to the level of the breeding value by milking: less than 100 kg (worst), -100 to +99 kg (neutral) and +100 kg of milk and more (best). In the group of bulls with an average positive breeding value, producers with a high proportion of the best daughters - Alku, Hialu and Oliver (More than 40%) were identified, as well as among producers with negative breeding value - with a high proportion of the worst daughters Accord, Unto and Centaur. For breeding work, the best producers are those whose high relative number of the best daughters does not depend on the breeding method, for example, Hial and Oliver. When using Kazbek and Etude, an intra-linear method should be used, and it is undesirable to use this method to obtain the descendants of Oliver and Lassie. In order to achieve a positive result with repeated use of the estimated bulls, it is necessary to test them not only in terms of breeding value by the milk yield of their daughters, derived by different methods, but also by the frequency of occurrence among them of offspring with a breeding level +100 kg of milk or more.