Optimization of standards for metabolic energy and crude protein for cows of Holstein dairy cattle population during the 2nd third of lactation

Abstract

The paper presents the results of studying the efficiency of moderately increased norms of requirements for both metabolizable energy and crude protein, as well as dry matter (respectively, up to 10%) in the diets for highly productive cows of Holstein population of dairy cattle of domestic selection for the Belarusian black-and-white breed in the 2nd third lactation on productivity and quality of milk, as well as homeostasis, digestibility of organic matter and use of nitrogen in the body of animals. The positive effect of moderately elevated requirements for the above nutritional components in diets with a predominance of bulky feed in relation to concentrates 53.0:47.0 instead of that in the control 51.9:48.1 on the above studied indicators.