Study of indexes of the suckling productivity the cows of Ayrshire breed of tribal economy of the Leningrad area

Abstract

In this article, studies the dynamics of indicators of the main signs of milk productivity over 305 days 7 lactations in 240 cows of the Ayrshire breed. The average values for milk yield, the mass fraction of fat and protein, the amount of milk fat and protein, the range between the maximum and minimum values were calculated and studied, and the standard deviation according to the characteristics studied was established. The average milk yield was higher in the 5th and 6th lactation and amounted to 8412 kg and 8962 kg; the maximum% of fat was in the 7th lactation - 4.2%, and% of the protein in the second - 3.46% and also in the last 7th lactation -3.43%. The value of the mass fraction of fat was maximum in the 1st lactation - 1.2; and the minimum at the 6th lactation is 0.05. The value of the mass fraction of protein was maximum in the second - 0.74 and minimum in the 7th lactation -0.24. He overall picture for these indicators represents the horizontal trend lines in the diagrams, which indicates a slight deviation of the values relative to the average for all lactations. The yield of milk fat and protein was maximum in the 6th lactation - 345.9 kg and 289.47 kg, respectively. The standard deviation by milk was 568.6; by mass fraction of fat 0.09; by the mass fraction of protein 0.08; by the amount of milk fat 26.4; by the amount of milk protein 16.9; which means the uniformity of the average values for these indicators. It can be concluded that the selection of cattle in this complex was progressive, because led to stably high production in animals over 7 lactations.