MILK PRODUCTION AND EXTERNAL CONFORMATION TRAITS OF COWS OF DIFFERENT PRODUCTION CAPACITY IN "IYULSKOE" EDUCATION FARM OF THE IZHEVSK STATE AGRICULTURAL ACADEMY
The article deals with the research of milk production and external conformation traits of cows of different production capacity in “Iyulskoe” education farm of the Izhevsk State Agricultural Academy. A group of cows discarded from 2012 to 2017 with completed lactation was selected for the research. All investigated livestock was divided into 3 groups according to the highest yield of milk per lactation: highly productive cows - with a yield of X+ 1σ; cows with record production capacity - X+ 2σ and production group - with a yield less than X+ 1σ. It is established that the record cows significantly exceeded the cows of other groups in milk yield for 305-day first and highest lactation, but were inferior in fat content by 0.09-0.21% (P≥0.99) and protein in milk by 0.01% (P≥0.95). According to the highest lactation, record cows significantly exceeded the yield of milk of highly productive cows by 1357.9 kg (P≥0.99), and production group by 3074.4 kg (P≥0.99) as well as the milk yields on average in herd by 2571.8 kg (P≥0.99). The coefficient of milk yield was higher in cows with record production capacity and exceeded the coefficient of milk yield in highly productive cows by 92.4 kg, on average in herd - by 166.3 kg, and in production group - by 197.5 kg (P≥0.99). There are no significant differences in milk production of cows of various lines in the groups. Among the record cows, the line V. B. Ideal 1013415 performed the highest production capacity of 10109.9 kg. In the group of highly productive cows, the differences in milk yield among the cows of different lines were in the range of 9.6-134.7 kg (P≤0.95). Among the cows in production group, the highest production capacity was performed by the line V. B. Ideal 1013415. The difference between the investigated groups of animals was insignificant according to all measurements of the 1st and the 3rd lactations.