The relationship of economic and useful traits in the Ural type cows of the black-and-white breed

Abstract

In the Sverdlovsk region, holsteinized black-and-white cattle of the Ural type are bred. All cows have high productivity indicators; the best milk yields are distinguished by the animals of the Vis Back Ideal line, which surpass their peers by 99 (Reflection Sovering line) and 1477 kg (Montwick Chieftain line) or by 0.9 – 13.7%. In the second case, the difference is significant at P≤0.01. According to the FMF in milk, higher values were observed in cows of the Montwick Chieftain line – 4.03±0.003%. They significantly surpass cows from other lines by 0.04 – 0.07% at P≤0.01, which did not affect the output of nutrients with milk. There is a stable high correlation between cow milk yield and milk fat yield with milk. The correlation coefficients approach one. A negative correlation was found between milk yield and fat mass fraction, which ranged from low (-0.03, Montwick Chieftain line) to medium (-0.34, Vis Back Ideal line). The average positive relationship between the fat mass fraction in milk and the amount of milk fat was found in cows of the lines of the Reflection Sovering and Vis Back Ideal

Assessment of influence of duration of the service period on the milk yield of cows

“…For its production, highly productive dairy cattle are used, the main livestock of which is represented by related breeds of Dutch origin -Holstein, Black-and-White mottled breed, etc. [13][14][15].…”

Dynamics of reproductive qualities of cows depending on the productive longevity

“…The gene pool of the Holstein breed, which is considered the best dairy breed in the world, for more than four decades has been widely used and continues to be used to improve domestic livestock, including the black-and-white mottled breed in order to increase plentiful milk yield and improve technological characteristics in industrial production [13][14][15][16][17].…”

Influence of inbreeding degree on the milk yield efficiency

“…For this, the semen of the best servicing Holstein bulls of foreign selection is purchased. Long holsteinization provided the positive results, it created the highly productive herds of Black-and-White dairy cattle, but it also increased the level of inbreeding [14][15][16][17]. In herds of some dairy farms in the region the number of cows born from closely related inbreeding achieved 85 and more percent of the total number of cows.…”