Influence of energy supply of diet of cows on dairy productivity and biochemical blood status

Abstract

In a research and production experiment carried out in the milk farm of «Klenovo-Chegodaevo» (Moscow) on two groups of holsteinized black-and-white cows with a milk yield of 7000 kg of milk per lactation, 20 heads each, it was found that an increase in the concentration of metabolic energy (CME) in the dry matter of the cows ration from 10,7 to 11,0 MJ/kg in the period from 21 to 120 days of lactation, due to the inclusion of protected fat in the diet of cows in the experimental group, in the amount of 300 g/head/day, produced on the basis of vegetable raw materials, contributed to an increase in milk yield of 4% fat and milk fat yield by 9,5% (p<0,05) for 120 days of lactation, while reducing feed costs for its production, expressed in CME by 5,4%. More intensive milking of cows in the experimental group in the new calving period had a positive effect on the tendency to increase milk yield of standard (4%) fat content and the yield of milk fat in general for 305 days of lactation by 7,4% (p>0,05), compared with control. Calculations of economic efficiency have shown that the use of fractionated fat in the amount of 300 g in the ration of high-yielding cows during the milking period from 10,7 to 11,0 MJ/kg can reduce the cost of 1 quintal of milk of base fat content (3,4%) produced by cows from the experimental group for the first 120 days of lactation by 43,6 rubles. or by 1.9% while receiving additional profit from its sale in comparison with the control in the amount of 3502,5 rubles. for 1 head. Biochemical studies of the blood of cows in the experimental groups, carried out on the 120th day of lactation, revealed a tendency for a more intense course of protein and lipid metabolism in the body of cows was revealed, who received a diet with an increased to 11,0 MJ/kg level of CME in dry matter of the diet, due to the use of protected vegetable fat in an amount of 300 g.