Assessment of productive longevity in cows of modern black-and-white cattle

Abstract

The Ural type of the domestic black-and-white breed is distinguished by high productivity indicators, good suitability for use in the conditions of industrial milk technology. High productivity is accompanied by a decrease in productive longevity, which raises new questions for livestock workers. The assessment of the productive longevity of cows, depending on belonging to the line, is relevant and has practical significance. As a result of the research, it was found that the highest lifetime milk yield had animals of the Siling Trijun Rokita line, which in this indicator exceeded the rest by 23015 - 30647 kg or by more than 54.0 - 72.0%. In each group there are animals that have low productivity and cows with a high lifetime milk yield of over 65-77 tons of milk. Cows of the Siling Trajun Rokita line have high rates of productive longevity – 5.9 lactation, and the other lines have low from 1.4 to 2.4 lactation. The genetic potential of productive longevity of cows of all lines (with the exception of the Pabs Governer line) is high 9 - 10 lactation. An increase in the duration of lactation does not significantly affect the overall milk productivity of cows.