Exterior and Body Types of Cows with Different Levels of Dairy Productivity

Abstract

The research aimed to study the dynamics of changes in the selection and genetic parameters of the body, to determine the relationship between the productive qualities and the exterior of cows in the population of Holsteinized black-and-white and Kholmogory cattle of the Udmurt Republic. Cows with a productivity level of more than 8000 kg of milk for 305 days of lactation had a relatively high indicator of the length of the coxal area (by 2.0 and 2.3%, P<0.05) and the depth of the loin (by 1.3 and 1.5%) with a slight difference in the length of the sacrum. High-productive cows had the smallest average conformation index of the body type (by 3.0%, P<0.05), which is evidence of the proportionality of the body, namely, the optimal ratio of the volume of the trunk to the animal growth. The harmony of bodybuilding is also evidenced by the index of the coxal area, defined as the ratio of the volume of the coxal area to the body length. High-productive cows had a more harmonious body, having the lowest value of this index (by 3.8%, P<0.01). A positive correlation was found between the conformational index of the body (r = +0.26), the index of the coxal area (r = +0.38), and the productive index. The origin of the animals had a definite impact on the level of dairy production. Cows of the wes back ideal line significantly (P<0.01) outperform their mates of the reflection sovereign lines by 693.65 kg (9.9%) and Montvic Chieftainby 827.82 kg (12.1%). The value of quality indicators of dairy productivity of cows testifies to an insignificant difference both in the fat content (by 0.02-0.03%) and in the protein content (by 0.02-0.03%) in milk.