Optimization of whole milk replacers compozition in calves` feeding

Abstract

The research and economic experiment aimed at determining the most effective ratio of milk and vegetable protein in whole milk replacers WMR. It was carried out in four groups of calves with an initial live weight of 39.2–41.2 kg at the age of 10–30 days. The research has shown that WMR No. 1 consisted of (% by weight): dried whey – 53, vegetable fat – 16, vegetable protein – 30, vitamin-mineral complex – 1, No. 2 – skimmed milk powder – 15, whey powder – 47, vegetable fat – 16, vegetable protein – 21, vitamin- mineral complex – 1.0, No. 3 – 30; 41.5; 16.0; 11.5; 1.0. The ratio of vegetable and milk protein in the experimental WMR is made: 46 : 54; 37 : 63; 27.5 : 72.5 respectively. 1 kg of dairy product contained: 16.9 MJ of metabolizable energy and 196-200 g of crude protein. There was no significant difference in the consumption of crude protein between the groups. This indicator ranged within 309–317 g. The raw fat level in 1 kg of dry matter of diets for young experimental groups ranged within 186.9-190.1 g, concentration of metabolizable energy in dry matter of diet in experimental groups is made 17.48–18.02 MJ. 12.4–12.8 g of digestible protein accounted for 1 kg of metabolizable energy. It was established that the total protein content in blood serum of animals in experimental groups ranged within 45.3–50.7 g/l, which is 7.1–19.9 % higher than the reference value. As for sugar level in blood, one can trace the metabolic activity of carbohydrate metabolism of experimental calves’ body. Feeding young animals with milk replacer promoted the increase of glucose level by 5.7–17.1 % in comparison with the coevals of the control group. As a result, it was determined that in control group the whole milk in diets allowed to obtain higher average daily weight gain of 565, and in the experimental groups – 435–505 g, which is 11.2–23.0 % less. The research has shown that despite of higher body weight gain in the experimental group IV, the lower cost of WMR in group II allowed to reduce the diet cost by 26.5–39.2 % and the cost price of weight gain by 18.0–29.5 % compared with animals of the control, III and IV experimental groups. Key words: feed, WMR, young cattle, performance, economic efficiency.