Influence of feed nutrients on some links of nitrogen metabolism in the organism of lacting cows in conditions of forest-steppe zone of Carpathian region

Abstract

The article is devoted to the study of certain parts of nitrogen metabolism in organisms of dairy cows under the influence of feed nutrients, in particular silage prepared from vetch-oat mixture using a preservative – probiotic preparat KT-L 18/1 (selection of probiotics laboratory of the Institute of Agricultural Microbiology) in dose of 8.0 ml of suspension per 1 ton of green mass.

The content of cereals in the mixture was 50.6 and legumes – 40.5 %. Herbs accounted 2.5 %. Using of probiotic by the silage preparation contributed to production of a quality product, the inclusion of which into the cows diets in the transition period minimized the deficit of dry matter (from 19.8 to 9.1 %) and protein (from 4.2 % to 2.1 %), and in the stall period respectively from 28.0 to 8.5 % by dry matter and from 10.1 to 0 % by protein. It was investigated that the feeding of silage prepared with probiotic had a corresponding effect on the intensity of nitrogen metabolism in cows. After 2 hours from the beginning of morning feeding there was a decrease in the rumen pH of experimental animals, which indicates an increase in the intensity of fermentation processes. The amine nitrogen content, which indicates the pool of free amino acids and the body's supply of nitrogen, was probably higher in the experimental group. Also in these animals was a decrease in the concentration of ammonia nitrogen against the background of increased nitrogen levels of free amino acids, which may be due, in particular, to more efficient use of ammonia microflora, as indicated by increasing protein nitrogen concentration, which is, as well as the activity of the microflora of probiotics, which promotes the production of a number of amino acids, enzymes and B vitamins. The  study of blood morphological parameters  was found that the level of erythrocytes and the degree of saturation of hemoglobin in the body of cows of both groups was within the physiological norm, although there is an obvious tendency to increase in experimental animals. Investigation of the serum protein spectrum shows a probable increase in the level of total protein and the concentration of γ-globulin fraction in the cows of the experimental group, which is partly due to the pronounced probiotic properties of silage prepared with probiotic KT-L 18/1.