Genetic Variability of Constitution Assessment of First-Calf Cows of Holstein Black-Spotted Breed of Different Lines

Abstract

Exterior assessment is important for specification of constitutional strength of an individual animal and its acclimatization ability, as well as its productive orientation. The object of our research was Holstein first-calf heifers of the black-and-white breed prevailing on the farms of Moscow region. Studies were conducted with application of linear estimation of the animal body type of 54,170 animals. Animals are divided into 5 groups depending on the lineage: Vis Back Ideal 1013415, Reflection Sovering 198998, Pabst Governer 882933, Montvik Chieftain 95679 and other lines. Most of the animals had parameters in the range of 4 ... 6 points. With greater reliability (p≤0.001) and in the course of the dispersion analysis, it was found that it affects the rump bone height, position of the quarters, the height of the back lobes, the length of the nipples, the width of the quarters and the angle of the back legs from the side (p≤0.01). The heritability of the rump bone height (0.27 ... 0.38) and milk type (0.16 ... 0.36) in almost of all studied lines was within moderate limits. A high occurrence of such constitutional defects as soft ankles (4.16 ... 13%), oblique udder bottom (1.78 ... 5.02%), high tail (2.75 ... 8.07%) and roof-like quarters (1.08 ... 3.77%) was noted in such lines of first-calf heifers as Vis Back Ideal 1013415, Reflection Sovering 198998 and Montvik Chieftain 95679. Animals of all the studied groups have high genetic correlations between the rump bone height and other parameters of constitutional assessment: Montvik Chieftain line has 95679 positive pairs 8 ( 0.63 ± 0.0032 ... 0.97 ± 0.0005) and 5 negative pairs (-0.66 ± 0.0041 ... -0.97 ± 0.0045); Vis Back Ideal 1013415 - 2 positive pairs (0.48 ± 0.0007... 0.66 ± 0.0006); Reflection Sovering 198998 - 4 positive pairs (0.41 ± 0.0009 ... 0.62 ± 0.0007); Pabst Governer 882933 - 3 positive (0.55 ± 0.0092 ... 0.74 ± 0.0071) and 2 negative pairs (-0.62 ± 0.0174). The obtained results reveal wide selection possibilities in dairy herds.