Optimization efficiency of protein and carbohydrate nutrition of highly productive cows
With high productivity of cows, the role of bypass protein increases. Its share may be increased by enriching the diet with high-protein supplements having a high «protection» degree of the protein against rumen microorganisms. The purpose of the work was to explain the optimization of diets of highly productive cows by equalizing the balance of degradable and bypass protein and fiber quality. The production experience was conducted on highly productive Holsteinized first-calf heifers during days in milk to achieve the set purposes. Diet optimization, use of Optimus feed protein supplement with a high proportion of bypass protein (84 %) in cow rations allowed to bring into compliance with the requirements the most significant nutritional indicators: dry matter, crude protein, degradable and bypass protein, fiber quality (ratio of ADF and NDF). Diet optimization contributed to its structure change, as a result, the amount of concentrated feed decreased to 36.9 % of the diet dry matter against 43.8 %. This contributed to cheaper diets, an increase in average daily milk yield in the first 100 days of lactation and, accordingly, for entire lactation; difference with the control values amounted 1287 kg (19.5 %). Increasing the fat and protein content in the milk of experienced cows increased the yield of milk fat and protein in the first 100 days of lactation by 18.6 kg (22.9 %) and 13.5 kg (20.3 %), respectively. When optimizing the diet for protein and fiber quality, eatability of the diet increased; lactation period decreased by 6 days. Blood biochemical parameters corresponded to the normal.