Влияние происхождения на молочную продуктивность коров черно-пестрой породы

One of the effective ways to improve the domestic black and motley breed of cattle is to breed along the lines. In this case, within a single line, there is a certain variety of expressed signs and properties of animals. Formation of dairy herds of breeding farms occurs, in particular, under the influence of used bulls-producers. The aim of scientific research was to study the influence of the origin of black-motley breed cows on their milk production. Studies were conducted in a herd of black-and-motley cows of the Sverdlovsk region. The indicators of milk productivity of cows are analyzed depending on the origin (line, bull-producer). It was found that during the first lactation of the cow, the Vis Vidiala lines exceeded the animals of the second and third groups by milk yield, respectively: during the period of expansion - by 49.9 (1.7%) and 23.3 kg (0.8%), in 305 days lactation - by 251.3 (3.0%) and 216.0 kg (2.5%); by the amount of milk protein obtained - by 6.0 (2.3%) and 8.2 kg (3.1%) (P <0.001). The mass fraction of fat in the milk of Montvik Chiftein cows exceeded that of the groups of cows belonging to the Vis Idyla and Reflection Sovering lines, respectively by 0.07 and 0.09% (P <0.001). In the first lactation period, the descendants of the bull Freed 105331968 led the way in milk yield. Thus, the milk yield for lactation in this group of cows is higher by an average of 1271.4 kg (13.5%) (P <0.001), 305 days of lactation - by 742.8 kg (9.1%) (P <0.001). And also the descendants of Friedom were high in milk protein compared to the daughters of other bulls (an average of 42.02 kg or 17.6%) (P <0.001). Cows, whose father was the bull Lobby 101916210, took the leading positions in the mass fraction of fat and protein in milk for 305 days of lactation. The difference with the average indicators of all daughters evaluated in this case was (P <0.001): for fat - 0.12%, for protein - 0.09%. Within one line there are animals with different levels of productivity. This once again proves the need to select high-yielding cows, including depending on the bull-producer.