Normalization of protein and carbohydrate nutrition for high productive cows during a dry period

Abstract

The article provides the results of study of protein and carbohydrate nutrition for high productive cows with milk yield of 10 thousand kg during dry period. There has been carried out the research for determining the feed protein disintegration and effectiveness of its use in cow rations. The carbohydrate nutrition for Holstein-Kholmogory cows during dry period taking into account quantity and quality of neutral detergent fiber (NDF) and acid detergent fiber (ADF) was studied. The science-economic experiment was conducted in the “Polyarnaya Zvezda”, Murmansk region in 2015 and 2021. The disintegration of feed crude protein (DP) was determined by the in sacco method, by incubation of average samples of single feeds in nylon bags in the rumen during 12 hours. Content of crude protein in feed samples before and after incubation was determined by the content of total nitrogen by the Kjeldahl method. Digestibility in the intestine of feed protein not disintegrated in rumen was determined by the mobile synthetic bag method. NDF and ADF were determined by the method of Van Soest and Southgate modified by N. N. Semina. In the experiment of protein nutrition, the content of crude protein in the ration of control and experimental groups of cows was 16 %. The content of disintegrated protein in the control group was 59.0 %, in the experimental group – 67.0 %. In the experiment of carbohydrate nutrition, in the control group crude fiber was 19.4 %, neutral detergent fiber – 38.9 %, acid detergent fiber – 23.0 % of dry matter. In the ration of experimental group of cows, the content of crude fiber was 22.4 %, neutral detergent fiber – 47.2 %, acid detergent fiber – 27.6 %. Animals of the experimental group whose ration had a crude protein disintegration of 67.0% used nitrogen more efficiently, utilized a nutritious of ration better. During the research it has been established, that the content of neutral detergent fiber of up to 47.2 % and acid detergent fiber of up to 27.6 % results in increase in digestibility of ration nutritious, improves nitrogen metabolism, intensify microbiological activity in cow rumen.