Ffects of synchronized carbohydrates and nitrogen feed components decay in rumen on the state of metabolism and productivity in dairy cows
The aim was to study the processes of rumenal digestion, taking into account the synchronization of protein and carbohydrate fermentation, the digestibility and assimilation of nutrients in dairy cows under stationary conditions, depending on the level of soluble protein and sugar in the diet. Three periods of the experiment were carried out on 3 cows of the Kholmogor breed in the middle of lactation, receiving rations with different ratios of the sum of sugar and soluble starch and soluble protein. The level of soluble protein was increased by the urea supplement, readily available carbohydrates by the inclusion of fodder molasses in the diet. It has been established that bringing the level of degradable protein in the diet to the normative values by the soluble protein leads to ineffective use of nitrogen in cows due to increased excretion of nitrogen in the urine. Adding readily available carbohydrates (molasses) to the diet can significantly reduce the excretion of nitrogen. At the same time, the optimal ratio of soluble protein to the sum of sugar and soluble starch was noted at the level of 0.41. The obtained data are proposed to be used as an additional physiological criterion for the adequacy of nutrition of highly productive dairy cows, taking into account the high-quality protein-carbohydrate ratio for cows early after calving with a high proportion of soluble protein in the diet.