CHARACTERISTICS OF DIGESTION IN HIGH-PRODUCING COWS: DEPENDENCE ON THE FAT CONСENTRATION IN THE RATION DRY MATTER.

Lipid metabolism in animals has recently gained growing interest among researchers. Among organic compounds, it is only protein and nucleic acids that for a long time have remained in primary focus of research, though lipids are now known to be essential for the origin of life and development of organic forms. Metabolic processes are very active in the bodies of high-producing cows. Large amounts of energy and nutrients are utilized to synthesize milk; all body systems function intensely. Consequently, there are increased demands for adequate supply of energy and all nutrients including lipids. Insufficient or excessive intake of the latter leads to disruption of metabolism, lower productivity, and deterioration of animal health. At present, there is some controversy in the Russian and foreign literature in regard to on the optimal fat content in the dry matter of the rations of lactating cows, especially high-producing ones. Researchers recommend rather wide ranges of fat concentrations in the diets. The issue that remains insufficiently explored is the effect of various fat levels on ruminal digestion processes, the pH of the rumen contents, concentrations of volatile fatty acids in the rumen, activity of symbiotic microorganisms, the size and species composition of microbiota in different parts of the digestive tract, as well as the key indicators characterizing digestion in high-producing cows.