In the conditions of the Republic of Belarus there was analyzed the efficiency of application of organic form of selenium Sel-plex in feeding of producer bulls. In course of the study there was showed the dynamics of live weight and average daily weight gain of producer bulls; blood indexes of analimals by the end of the experiment; sperm quality of experimental bulls. As a result of research it was established, that application of organic form of selenium Sel-plex in feeding of breeding bulls during the summer and winter periods in a dose of 0,4 mg/kg of dry matter of a ration promoted the increasing of daily average live weight gain on 6,4-8,1%, improvement of morphological and biochemical blood structure, increasing of indices of natural resistance on 0,5-6,1% and sperm production quality - on 7,3-28,0%.

In the conditions of the Republic of Belarus there was analyzed the efficiency of administration of nonconventional feed materials in diets of highly productive cows and its influence of indexes of natural resistance at different physiological stages of animals. In the process of studying of adaptation processes of highly productive cows at different stages of lactation it was determined that feeding with nonconventional melanoidin-humic additives at different physiological periods rendered a positive influence of highly productive cows, promoted the increasing of natural resistance of animals and improvement of immuno-humoral blood indexes. Administration of an additive Ehkolin in a ration of highly productive cows with stimulation for increasing milk flow in a dose of 100 ml per head promoted the increasing of blood serum bactericidal activity on 5,2%, beta-lysine activity - on 7,2%. Feeding of animals at a basic lactation period with 50 ml of preparation Ehkolin-2 provided the maximum increasing of lysozyme activity of blood serum (on 6,2%) and beta-lysine activity of blood serum (on 12,7%), and also promoted the activation of leukocytopoiesis. Addition of Ehkolin-3 in ration structure of dry cows in a dose of 750 ml increased the indexes of lysozyme activity of blood serum on 7-8,6%, bactericidal activity of blood serum - on 2,2-3,6% and beta-lysine activity of blood serum - on 2,2-3,6%.

In the conditions of the Republic of Belarus there was studied the efficiency of application of granulated and extruded lupine (Lupinus) in feeding of bull claves. It was determined that after lupine extruding the quantity of sugar in it increased on 45% due to lowering of starch content. The inclusion of extruded lupine into bull calves diets made it possible to increase the digestibility of dry and organic substances, protein and nitrogen-free extractive substances. The highest average daily weight gain (842 gram) was stated at claves which were fed with mixed fodder with 15% of extruded lupine; this was on 7,5% than in a control group. In the conditions of feeding with the granulated lupine the average daily weight gain increased on 5,3% in comparison with crushed one. In course of study there was analyzed the dependence chemical composition of lupine on the processing method; blood composition of the studied animals; diets of experimental animals; digestibility of nutrient substances of forages; balance and intake of nitrogen; biochemical blood composition; changes of live weight and average daily weight gain.

Research on working out of a new fodder additive on the basis of rape (Brassica napus) phospholipids which included mineral substances necessary for normal functioning of cattle was realized in the conditions of the Republic of Belarus. Results of biochemical analysis of 35240 blood samples revealed that 15-40% of studied animals had abnormalties in vitamin, protein and mineral metabolism and lowering of immunobiological disease resistance. There was correlation dependence between the degree of metabolic orders and the state of forage reserve of a forage reserve. The lowering of forage reserve caused the increasing of metabolic disorders. As a whole forages of the surveyed farms were low in content of copper, zinc, cobalt and selenium and could not provide physiological requirements of animals without introduction into rations of specialized additives

Investigation of stress reaction response and productivity of poultry by means of stimulation of natural resistance by biologically active substances was realized in the conditions of the Republic of Belarus by an example of 4 experimental group of broiler chickens of Kobb-500 cross. The first group was a control one. Chickens of the second group were administrated preparation Vigozin twofold in dose of 1 ml/l with water in course of the first three days in 2 cycles and with interval of 8 days. Chickens of the third group were given the preparation with water in dose of 1 ml/1 in course of the first 3 days. The fourth group was given the preparation with water in dose of 1 ml/1 in course of the first 5 days. In course of observation over chickens there was analyzed their clinical state, mortality rate, weight gain, and meat yield. In course of study in chickens of experimental group the daily average weight gain was 37,8 g against 34,1 in control; average live weight – 1099,6 +/- 7,57 g against 95,98 +/- 0,50 g in control. In 46-day old broiler chickens the average daily weight gain was 46,2 g against 43,1 g in control, average live weight – 2166,94 +/- 0,49 g against 2021,08 +/- 1,05 g in control. Forage expenses per 1 kg of weight gain were 2,01 kg against 2,18 kg in control. Forage conversion was 7,8%. Research results proved the efficiency of application of Vigozin preparation: viability of chickens in the second group on increased 3,5%; the third group - on 1,7% ; in the fourth group - on 2,5%

Influence of monocalcium phosphate on natural resistance and clinical indexes of blood of breeding bull calves of white-and-black breed was realized in the conditions of the Republic of Belarus. Bull calves of the first (control) group in the composition of their main ration were fed with mixed fodder K-66-b, hay, green mass and as a balanced phosphoric-potassium additive they were fed with8 grams of defluorinated phosphate per 1 kg of mixed feed. Bulls of the second, third and fourth experimental groups in combination with the standard ration instead of difluoridated phosphate were fed with 5; 10; and 15 grams monocalcium phosphate per 1 kg of combined feed, respectively. Research results showed that application of fodder monocalcium phosphate in addition to the main ration made it possible to increase calcium and phosphorus content in blood of experimental bull calves. In the control group phosphorous content was 2,17 micromole, in the experimental groups – 2,40-2,78 micromole; calcium content – 2,50 and 2,58-2,88 micromole, respectively. The analyzed additive rendered positive effect on protein exchange, increased the natural resistance, bacterial growth-inhibitory activity in blood serum in the third, fourth and second groups on 50,3%, 42,5%, and 40,3%, respectively; lysozyme activity – on 46,0%, 39,2%, and 32,3%, respectively; phagocytic activity of leukocytes – on 21,9%, 25%, and 19,1%

Development of axial skeleton bones of meat type broiler chickens of Kobb-500 and Ross-308 crosses at the postnatal ontogenesis period was investigated in the conditions of the Republic of Belarus. In course of studies there were used broilers of 5 age groups (1 day old, 20 days old, 30 days old and 40 days old) which were selected in accordance with analogous principle with 10 heads per each group. Research results showed that live weight gain as well as axial skeleton weight gain of both crosses chickens increased wavily. The highest growth intensity of body weight and axial skeleton weight was stated at broiler chickens of Kobb-500 cross at the last age period. The opposite way, there was noted the increasing of axial skeleton growth for broiler chickens of Ross-308 cross at the age of 20 days. At the further age periods till the end of fattening-off there was stated the slowing of axial skeleton and body weight. In the period of 1 to 10 days there was stated an intensive growth of cervical spine of spinal column of broiler chickens of both crosses. High intensity of absolute weight growth of cervical spine of spinal column for Kobb-500 cross chickens was stated at the age period 30-40 days; for Ross-308 cross chickens - at the age 10-20 days

Results of researches on studying influence separate and combination feeding fermented compositions Fekord-2004C and biologically active additive Oxide Peat on energy of growth and protective properties of an organism of pigs – deprivation are stated. It is established that enrichment of mixed fodder investigated by the fodder fermented additive Fekord-2004C at the rate of 0,15 kg on ton of mixed fodder in combination application with biologically active substance Oxide Peat in a doze of 1,0 kg on ton of mixed fodder promotes increase of growth rate of pigs on development and to decrease of the charge of forages on unit of a gain of alive weight and safety of pigs

While studying biochemical values that characterize rumen digestibility based on research agricultural experiment some results were obtained. These results prove that studied diets with increase of energy and raw protein concentration levels in dry matter influence positively at nitrous substances concentration activate micro flora motions and promote bio-synthetic processes in rumen fluid of experimental animals

Increase of diets nutrition energy in our experiment showed no significant effect on usage of nitrogen in feeds. Diets with different energy levels have no negative effect on hematological indices of animals