Feed costs and indicators of reproductive capacity of high-yielding cows at different levels of Bypass soybeans in rations
Abstract
The article presents the results of a scientific and economic experiment to study the influence of different levels of Bypass soybeans in the diets of high-yielding cows on feed costs per kilogram of milk and reproductive functions of cows. Provision of the rations of the experimental cows with an unequal amount of the difficult-to-dissolve fraction of crude protein, at the expense of Bypass soybeans, affected their consumption of bulk feed. The experimental cows consumed 4.1–4.8 kg from the specified 5 kg of alfalfa hay, 20.8–24.6 kg from 25 kg of corn silage, and 8.4–9.7 kg from 10 kg of alfalfa hay. The consumed feed provided cows with crude protein at the level of 16.0–16.5 % of the dry matter, its poorly soluble fraction at the level of 27.3 % of the crude protein in the 1st control group, 31.1 % in the 2nd experimental group, 35.2 % – in the 3rd experimental group and 40.0 % – in the 4th experimental group. The sugar-starch-protein ratio was normal and ranged from 2.20 to 2.28 : 1 with a norm of 2.1 : 1. The micronutrient rations were balanced due to micronutrients of organic origin. On the basis of the obtained data, it was proved that the lowest feed consumption per 1 kg of milk was observed in cows of the 4th experimental group, which were fed rations with 2 kg of Bypass soybeans, where the level of insoluble protein was 40 % of crude protein and these consumptions were 6.5 MJ against 7.4 MJ in the 1st control group. Cows of the 4th experimental group also had the best insemination and service period indicators. The duration of the service period in the experimental groups was less in percentage compared to the animals of the 1st control group by: 15.0 in the 2nd; 25.6 in the 3rd and 32.9 in the 4th. Partial and complete replacement in the diets of cows of the 2nd, 3rd and 4th experimental groups of soybean meal with Vypass soybeans at the level of 1.0; 1.7 and 2 kg of compound feed concentrate in the first 100 days of lactation has a positive effect on the physiological state, stimulates appetite and provides normal conditions for fertilization and embryo development.
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