Assessment of Rumen Digestion Processes and Productivity of Fattening Bull Calves with a High Level of Concentrates in the Diet

Abstract

Low-quality protein in the diet of animals leads to excessive formation of a by-product in the rumen in the form of ammonia. Formed ammonia does not participate in the synthesis of microbial protein and excretes in the urine and leads to additional energy costs. The aim of the research is to determine the optimal level of stable protein consumption, which allows to completely provide the growing animal organism with protein, as a guarantee of future health and productivity potential and an barrier to the development of rumen pathologies. Researches were conducted on calves of the Kholmogory breed raised in the VNIIFBIP vivarium from the age of 40 days to 14months.Milk substitute feeding was carried out until the age of 70 days with free access to compound feed and hay. In the after milk period, the bull-calves received compound feed, hay and silage. To study the effect of concentrated feed on metabolic processes and nutrient digestibility, factors of rumen digestion were studied. It was found that the physiological and biochemical parameters fit into the reference values. The proportional intake of concentrated feed together with coarse feed with intensive rearing and fattening of dairy bulls and the normal course of enzymatic processes in the rumen and throughout the body allows achieving an average daily increase of up to 1420 g by the age of 14 months. The results obtained are most significant and cost-effective, especially in regions with a large number of dairy cattle and low cost of concentrated feed.