Belarus is included into number of the leading countries of the world which provide the increasing of the expansion rates of milk production and dairy products on a per capita basis. However, the agricultural enterprises of the Republic of Belarus annually spend approximately 800 thousand tons of whole milk that makes about 20% from the general milk yield for manufacturing expenditures in the process of livestock operation. The purpose of research was working out of a new premix structure and zootechnic requirements to its use in structure of milk replacer, produced on hydrodynamic installation. The optimum doses of amino acids, vitamins and mineral substances promoted the increasing of calves daily average weight gain during the dairy period on 5,4% (788,5 g instead of 748,1 g), reducing of expenses for forages per 1 kg of weight gain - on 6,5% (2,9 fodder units against 3,1 fodder units) and the decreasing of the prime cost production for fodder expenses - on 4,7%. There was presented the composition and nutritive value of the analysed whole milk replacer. Usage of local sources of protein-fatty raw materials of plant origin, and also secondary resources of processing of whole milk in the content of milk replacer for young cattle allows to completely refuse from expensive components delivered from abroad and to lower their cost

Research on preserving ability of the biological preserving agent Bioplant for grass and maize silage making was realized in the conditions of the Republic of Belarus. Application of Bioplant in course of grasess and maize encilaging promoted the faster accumulation of the significant amount of milk acid and decreasing of рН up to 4,1-4,2. Silage which was prepared with preserving agent Bioplant corresponded to the top grade of quality. Application of Bioplant for preparation of siloed forages promoted the reduction of losses at their storage. For example, in grass-legume and cereal silage there was a reduction of dry matter losses in comparison with control silage - on 4,7 and 4,2%, crude protein - on 5,6 and 5,0%, respectively. In maize silage the addition of the preserving agent there was stated the decreasing of nutrient losses in comparison with the control: dry matter - on 5,2%, crude protein - on 6,2%. Feeding of wedder hogs with the silage preserved by the preserving agent Bioplant provided higher digestibility of crude protein in comparison with the control group: on 3,2% in the conditions of grass-legume silage use, on 2,4% - in the conditions of feeding with cereals, and on 2,9% - in the conditions of feeding with maize silage

Determination of the efficiency of young fat stock feeding with wet rolled maize grain which was preserved by means of different preparations was realized in the conditions of the Republic of Belarus. The following preserving agents were applied: HV-2 (by- product of amino-formaldehyde resin); AIV 3 Plus (mixture of 62% formic acid and 24% ammonium formate; KEMIRA, Finland); carbamide (30 kg/t) with 40 g/t of complex mineral supplement. Feeding of young fat stock with rolled maize grains preserved by NV-2 promoted the increasing of nutrient digestibility on 1,5-5,0%, nitrogen use - on 2% in comparison with control. Application of rolled maize grain preserved with AIV-3Plus and carbamide with the complex mineral supplement made it possible to increase the digestibility of nutrients on 1,0-4,8% and nitrogen use - on 1,6-1,7%. Introduction of rolled maize grain preserved with NV-2 into rations of bull calves increased their productivity on 4,7% (P less than 0,05) with the simultaneous lowering of forage expenses on 1,9%. Application rolled maize grains preserved with AIV-3Plus made it possible to increase daily average weight gain on 3,8% and lower the forages expenses on 2,6%. Use preserved with NV-2 and AIV-3Plus rolled maize grains in rations of young fat stock lowered the production cost price on 11,9% and 10,8% that proved the efficiency of the studied fodder

Evaluation of maize (Zea mays) silage prepared in combination with biological preserving agent Laktotim and calculation of its economic efficiency were realized in the conditions of the Republic of Belarus. Application of Laktotim rendered positive influence on forage dry matter content, on nutritive substance safety, and made it possible to increase the organoleptic indicators of silage. Use of the maize silage prepared with the preservative in a cow ration has positively affected their dairy efficiency. Cow milk yields have raised on 4,5%. Application of the preparation for silage making of green maize mass proved to be economically worth. The realized toxicological estimation of biological preserving agent Laktotim did not reveal any signs of preparation toxicity. Introduction of the preparation into mice stomach in a single maximum dose (25000 mg/kg; 12500; 5000 mg/kg of body weight), as well as application of the preparation in mixture with water in ratio which in 100 and 200 times exceeded the standard ratio in plant green mass, did not cause destruction of experimental animals. According to classifications of All-Union State Standard 12.1.007-76, the preparation Laktotim belongs to the4 class of danger - low-hazardous substances (LD50 over 5000 mg/kg)

In the conditions of application of enzyme preparations there is the possibility of inclusion into mixed fodders structure of such cheap fodder grains as rye. Determination of the optimal dose of introduction of the liquid enzymatic fodder additive (xylanase – 8800 units; phytase – 600 units; cellulose – 880 units; r-gluco – 4000 units; a- amylase – 200 units) and its influence on stores productivity during the completion of growing and fattening periods was realized in the conditions of the Republic of Belarus. Research results showed the following: inclusion into mixed fodders of the increased amount of rye grain (without the enzyme additive) for stores feeding during the completion of growing (20%) and fattening (30%) periods did not render negative influence on experimental animals; the optimal dose of the trial enzyme for stores during the completion of growing period - (SK-21 including rye grain - 20%) was 200 ml per 1 t of mixed fodders; the optimal dose of the trial enzyme for stores during the fattening period (KDS-26 including rye -30%) was 150 ml per 1 t of mixed fodders. Application of the experimental fodder additive promoted the increasing live weight gain. There was noted the tendency of the positive influence of the analyzed enzyme on dry and organic matter, fat, dietary fibre and nitrogen-free extractive substances digestibility

The comparative analysis of application of cereal ensilage produced with addition of microbial and enzymatic preserving agents Axphast Gold and Biotrof on fodder digestibility, hematological indexes and cicatrical digestion of cattle rearers was realized in the conditions of the Republic of Belarus. Cattle feeding with the analysed silage rendered positive effect on digestibility of the forage dry matter, which was on 2% higher the control index, organic matter - on 2,4%, nitrogen-free extractive substances - on 2,84%, fat - on 0,58%, protein - on 2,3%, cellulose - on 2,1%. Use in feeding of ensilaged forages from the cereal perennial grasses preserved by the microbial- enzymatic preparation produced by company Biota rendered the positive influence on use of nitrogen, calcium and phosphorus. There was also noted the increasing of the content of volatile fatty acids in paunch of young cattle silage fed with Axphast Gold that testified of more effective utilization of forage

Research was directed towards selection of national, accessible and cheap ingredients of whole milk replacers in the conditions of the Republic of Belarus. The efficiency of compounding preparation and its use in calves feeding at an early age was analysed. There was developed the technological scheme of application of hydrodynamic installation which operates according cavitating principle and makes it possible to receive the homogeneous and finely divided mass directly from grain forage that is very important for preparation of milk replacer. New equipment gives the chance to lower power consumption on 17%, to receive economic benefit. During testing of developed of milk replacer-1 (used for calves feeding since one month old) and milk replacer-2 (used for calves feeding since two months old) and their comparison with the whole milk replacer Kalvolak (the Netherlands) it was revealed, that indices of a daily average weight gain in calves of the first group fed with foreign milk replacer, and in calves of the second groups, which were fed with the national milk replacer, did not show authentic differences (806 and 816 g). However, the prime cost of 1kg of live weight gain in the second case was on 43% cheaper than in the first one. The cost price of 1kg of live weight gain of calves on expenses for fodder units in trial group was on 33% cheaper in comparison with the control group

In conditions of the Republic of Belarus much attention is given to optimization of energy and protein content in diets of dry cows. Analysis of the influence of different energy and protein ratio in dry cows diets on their productivity was realized. Increasing of protein and energy balance standards of dry cows during the winter period on 10 and 15% at the expense of introduction of protein, vitamin and mineral supplements (PVMS) made it possible to increase the daily average weight gain of animals on 5,4% and 12,2%, live weight of calves at a birth on 3,6% and 8,1% and their daily average weight gain over the first month - on 3,9% and 12,1%, respectively. Feeding with PVMS produced on the basis of peas and rape made it possible to raise the digestibility of nutritive substance on 1,4-14% and accessibility of all mineral substances on 0,4-10%. The increasing of energy and protein ratio on 15% in diets of pregnant dry cows rendered the positive effect on dairy efficiency. Fodder expenses for fodder unit production decreased on 5,5 and 6,8%, respectively. Inclusion of PVMS in mixture with pea and rape flour for dry pregnant cows during the summer period made it possible to raise their live weight on 5,9% and 9,7%, weight of calves at birth on 4,2% and 7,3%, and their daily average weight gain - on 5,7 and 9,4%. Optimization of power and protein fodder of pregnant dry cows promotes the increasing of milk yields in the first 100 days of the subsequent lactation on 5,1% and 9,9% and the decreasing of forage expenses for production unit on 4,6-9,1%