The feeding of carboxyline and cobalt salts to cattle young fattener receiving the concentrate-silo rations with synthetic nitrogen-containing substances (diammonium phosphate and urea) is accompanied by an increase in the concentration of bicarbonates and CO2 in blood and citric acid in blood plasma with a decrease of the ketonic bodies content in it. The level of carbon dioxide in tissues being increased, the content of ammonium nitrogen in the rumen fluid lowers and the activity of transaminases in blood plasma, the content of glutamate in the liver and that of urea in the rumen fluid increase which evidences for an intensified transformation of the ration nitrogen in the organism. The performance of animals is increased.