Investigation of influence of probiotic Dialact and immunostimulant Alveozan on digesting of nutritive substances by broiler chickens of Kobb-500 cross, as well as control over their individual development were realized in the conditions of the Republic of Belarus. The first (control) group of chicken was given standard well-balanced ration. Chickens of the second group were administrated immunostimulant Alveozan in dose of 10 mkg/kg of live weight with drinking water once a day in course of 5 days, with 10 days interval till the end of the growing period. Chickens of the third group were administrated preparation Dialact in dose of 0,1-0,2 ml with drinking water once a day in course of 3 days, with 14 days interval till the end of growing period. Chickens of the fourth group were given Alveozan in dose of 10 microgram/kg of live weight once a day in course of 5 days with 10 days interval, and Dialact in dose 0,1-0,2 ml once a day in course of 3 days, with 6 and 14 days interval. Research results showed that complex application of probiotic Dialact and immunostimulant Alveozan increased the viability of chickens on 100%, average live weight - on 5,1%, average daily weight gain - on 5,1%. Administration of Dialact and Alveozan, both separately and in complex, increased the digestibility of nutritive substances of mixed fodders: application of nitrogen increased on 1,93-6,38%, application of calcium decreased on 10,41-12,54%, phosphorus use increased on 2,38%

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

In the physiological experience spent on male pigs-manufacturers, we had been studied influence of various doses of selenium (10 mg, 20 and 30 mg) in structure premix on nutrients. It is established, that increase of level of selenium in mixed fodders for male pigs-manufacturers to 30 mg/kg especially promotes increase in degree of use in their organism of fat to 58,7%; (P less than 0,05), the digested nitrogen to 62,1%, calcium – to 78,3% and phosphorus – to 72,5%

Determination of influence of combined feed with carnitine and 3% lipids on digestibility of nutrients in ration of fattening stores was realized in the conditions of the Republic of Belarus by an example of 8 castrated male pigs of Belarusian meaty breed with body weight of 60-65 kg. Piglets were divided into 2 groups in accordance with analogue pair principle. Selected animals were kept in single cages specially equipped for fecal and urina gathering. Both groups of animals were given the same combined feed SK-26 which included 3% lipids. Experimental piglets were fed with combined feed with carnitine in dose of 50 g/t of mixed fodder. The mixed fodder contained the following ingredients: wheat; triticale; grain mixture; sunflower oil cakes; liprot SG; tricalcium phosphate; calcium carbonate; salt; premix KS-4; vegetable oil. Research results showed that enriching of combined feed carnitine rendered positive influence on digestibility and absorbency of nutrients. It made it possible to increase the digestibility of dry matter on 2,1%, organic matter on 2,0%, crude protein on 3,1%, crude fat on 7,4%, crude fiber on 8,6%, free-nitrogen extract on 1,1%, as well as to increase nitrogen, calcium and phosphorus absorbency. Quantity of saved nitrogen in the experimental group (with carnitine additive) was on 21,1% than in control one. Quantity of saved nitrogen and absorbed with feed was on 9,8% and 5,6% respectively higher than the same indexes for the control group; calcium - on 15,5% and 2,6%, phosphorus - on 23,3% and 3,7%, respectively

The research in RUP Scientific and Practical Center of Animal Breeding of National Academy of Sciences on such parameters as consumption of forages, processes of rumen digestion, morphological and biochemical structure of blood has shown that usage of wet grain preserved with Kormoplus for young cattle fattening has a positive effect on physiological condition and digestibility of nutrients and promotes nitrogen usage by animals that increases at 7,0 and 1,6%

Usage of preservatives Kormoplus 1 and 2 lets us produce the silage of a highest quality and raise dry substance integrity at 8,7%, protein - at 12-9,4%. The researches determined that cereal silage, prepared with supplement Kormoplus 1 and 2, lets us raise digestibility of dry substance at 5,5% and 3,7%, organic substance - at t 5,5 and 4,0%, fiber- at 16,5 and 15,0% and raise nitrogen sediment at 17,4 and 20,8%. These forages didn't have any negative influence at health and biochemical performance of cow blood

It is determined that diets with protein digestibility of 61-66% in organism of a calve activate fermentative processes in rumen, increase digestibility of nutrients at 3,8-10,1% that allows to obtain the average weigh gains of 1036-1075 g, that is at 4,2-8,1% higher than that of control group at forage spends of 6,79-7,04 forage units