Balanced complete feeding proved to be one of the major conditions of animal productivity increase and improvement of their reproductive qualities. Full value of feeding could be obtained at the expense of forage quality improvement and perfection of structure of the rations providing the increasing of metabolic energy use by breeding bull-calves. Analysis of the efficiency of metabolic energy use by the replacement bull calves under conditions of various sugar and protein ratio was realized in the Republic of Belarus. Research results showed that enrichment of replacement bull calves (with 325-405 kg of live weight) rations with easy digestible carbohydrates (sugar and starch) in ratio of 32% from a dry matter ration, including 15% of stable starch made it possible to increase the transformation of metabolic energy into energy of body weight gain on 21,73 - 23,96 MJ or on 10,3%, that as a result correspondingly increased the daily average weight gains on 7,9% and reduced the expenses for forage energy for 7,1% counting on an energy unit. According to the ejaculate volume indices the bull calves of the second experimental group surpassed analogues of a control group on 14,8%, and according to sperm concentration indices - on 12%. The average quantity of the frozen doses of sperm has made 65%

Studying of interaction of phytolectins with carbohydrate epitopes of cattle erythrocytes and alpha 1-4 D-glukan was realize in the conditions of the Republic of Belarus was realized by the example of seeds of soy (Glycine max) of Viliya variety, common bean (Phaseolus vulgaris) of Olga variety, spring barley (Hordeum vulgare) of VM-MGF variety, and wheat (Triticum aestivum) of Akogomugi varity. Lectins studies of pathological conditions (infringement of a cellular metabolism, transformation and cell destruction, etc.) were closely connected with research of structure and functions of cellular membranes that was important for carrying out of various biotechnological works. As a result of the realized research there was given the comparative characteristic of hemagglutinin activity of phytolectins of some bean and grain crops in relation to erythrocytes of cattle and precipitating with and 1-4 D-glukan. Intensive precipitation of alpha 1-4 D-glukan was observed in the conditions of its interaction with lectins of soya and wheat and less expressed in the conditions of interaction with lectins of bean and barley. It was established, that glucose monomers and its derivatives proved to be the basic structural element of glycocalyx of erythrocytes which detected the phytolectins of soya, beans, wheat and barley