Assessment of selection groups of mature cows of various breeds, differentiated by milk fat

Abstract

The assessment of black-and-white, red steppe, and Simmental cattle, differentiated by milk fat was carried out. Three groups were formed: selection, production and marriage. The selection parameters are calculated using the standard deviation. The calculated parameters of selection of animals of the breeding group for milk fat in adult black-and-white cows are at least 179 kg, red steppe - 186, Simmental breed from the Novosibirsk region - 143, the Republic of Khakassia - 176 kg. Cows of the red steppe breeding group are leading in productivity. Their milk fat index is 216.8 kg (P ≥ 0.95). In animals of the black-and-white breed, the milk fat productivity is 193.2 kg. In the Simmental Republic of Khakassia it is 193.8, in the Novosibirsk region - 163.5 kg. Analysis of interbreed differences in cows of breeding groups shows that animals of the black-and-white breed surpass their peers in chest width behind the shoulder blades, milk yield and milk production index. Animals of the red steppe breed are the best in milk fat, live weight, width in shanks, oblique body length, oblique rear length, chest girth, milk fat content. Simmental cows bred in the Novosibirsk region lead over their peers in height at the withers, and Simmental cows in Khakassia - in height at the sacrum, chest depth, cannon girth, assessment of the exterior. Evaluation of the production groups of animals for milk fat allows to note that the selection group of the black-and-white breed, despite the superiority in milk yield, is inferior to the peers of the red steppe and Simmental in terms of the evaluated character. However, the cows of the black-and-white breed of the production group surpass their peers in milk fat and most other signs. The formation of breeding groups for milk fat enables to note the consolidation of the black-and-white breed in terms of productive and exterior characteristics. The Red Steppe and Simmental breeds have a high potential for improvement. These breeding groups are worthy of competing with the contemporaries of the black-andwhite breed in milk fat productivity.