Exterior Features of Cows of Different Breeds and Interbreed Types

Abstract

The purpose of the research was to determine the features of the exterior of first-calf heifers of different breeds, interbreed types and the influence of conditional blood by improving breeds. The exterior was evaluated in the herd of dairy cattle of the "Rosiya" breeding farm of the Donetsk region of 111 first-calf heifers Angler (AN), 28 – Red Danish (RD), 2034 – Ukrainian Red Dairy (URD), 69 – Ukrainian Black-and-White Dairy (UBWD) and 16 – Holstein (H) breeds by the methods of instrumental (10 measurements), visual (10 linear descriptive signs of type) assessment and calculation of body structure indices. Among the URD, 700 animals are classified as fat-milk (FRD) and 1334 – to holsteinized (HRD) interbreed types. A significant level of interbreeding differentiation of first-calf heifers was established based on the evaluated external features. In the first-calf heifers of the H, UBWD and URD breeds, better development in height, chest and rump, as well as a general improvement in body structure, was noted. The first-calf heifers of the AN and RD breeds are characterized by the largest diameters of the length of the body and the smallest - the circumference of the shin. According to the exterior, two identical clusters of breeds and types are defined. The first includes animals of AN, RD breeds and FRD, the second – first-calf heifers of H, UBWD and HRD. The use of the H breed in crossbreeding shifts the proportions of the cow's exterior in the direction of increased height, long legs, relative narrow-chested, lowness, eyrisomia, and RD and AN – in the direction of stretched, bony, massive and overgrown. At the same time, the interbreed differentiation into quality groups according to the exterior and milk yield of HRD and FRD within a single URD exceeds in many cases the interbreed difference of the Holstein cluster (URD, UBWD, H). It was established by the analysis of variance that breed affiliation determines 0.3...7.5% of the total phenotypic variability of the exterior of first-calf heifers, and conditional blood by the H breed – 1.7...56.2%. Conditional blood by the H breed shows a direct reliable relationship with height at the withers (r = 66.0 ± 1.57%), rump (63.1 ± 1.62%), depth (22.4 ± 2.03%) and girth of the chest (42.7 ± 1.89%), width of buttocks (28.6 ± 2.00%), length of rump (21.2 ± 2.13%) and circumference of the shin (33.3 ± 1.97%). The width of the chest increases with an increase in conditional blood in the AN breed (15.0 ± 2.06%), and the length of body - in the RD breed (12.5 ± 2.07%). The established (correlation analysis) level and direction of the relative variability of conditional blood for improving breeds with exterior and milking traits confirms the expediency and perspective of using the H gene pool and the impracticality of further use of AN, RD and FRD.