Improvement of the standards of energy and protein diets of young stock cattle of 1-6 month old and determination of its influence on animal productivity was realized in the conditions of the Republic of Belarus. The studied made it possible to determine that at the age of 1 month the calf diet should contain 1,02 kg of dry matter and 21,2 MJ of metabolic energy; at the age of 2 months - 1,26 kg and 23,5 MJ; at the age of 3 months - 2,2 kg and 25,6 MJ; at the age of 4 months - 2,9 kg and 31 MJ; at the age of 5 months - 3,28 kg and 34,2 MJ; at the age of 6 months - 3,76 kg and 37,6 MJ, respectively. Metabolic energy concentration per 1 kg of dry matter should not be lower than 20,7 MJ at the first month, 19 MJ - at the second month, after the third month it should lower up to 10 MJ. In course of 6 months the presented diet scheme made it possible get 832 g of average weight gain in the conditions of forage expenses of 3,52 forage units per 1 kg

Feeding replacement calves of 369-460,8 kg of live weight with diets of non-degradable protein level that is 10% higher than approved norm increases metabolically energy transformation into weight gain energy from 19,10 to 20,81 MJ or at 9% that promotes increase of average daily weight gains at 5% and decrease of energy spends at 5% counted per 1 unit of energy for weight gain. Ejaculate volume is increased at 14% and sperm concentration – at 12%

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

Balancing of mixed feeds for replacement gilts considering the metabolically energy level and essential available amino acids amount increases growth speed of animals at 9,6% (P less than 0,05) compared to mixed feeds prepared in correspondence with detailed norms of feeding; it also decreases terms of animals pedigree usage from 277 to 223 days

Traditional raw materials in Belarus for mixed fodders production are wheat, barley, oats, rye, peas, lupine, sunflower and rape cakes, bran. However, productive action of these forages is limited because of presence of antinutritious factors and the raised cellulose content. In the Republic of Belarus there was organized production of national enzyme fodder additive Fekord 2004. Peculiar feature of the presented enzyme complex was addition of into its structure of enzyme glucoamylase, promoting hydrolytic starch splitting, and accordingly, the increasing of absorbency of difficult carbohydrates of forages. It was especially important for stores at early stages. Thereupon it was expedient to study the efficiency of application specified multienzyme composition in diets of growing and fattened stores. It was established, that enrichment of mixed fodder with the analysed fodder fermental additive at the rate of 0,13 and 0,15 kg per ton of mixed fodder made it possible to increase the growth rate of pigs and lower charges for forages per unit of body weight gain. Higher economic return on the fodder enzymic additive an additional gain of body weight appeared at its introduction in quantity of 0,15 kg per ton of mixed fodder

In the Republic of Belarus the grain part of mixed fodders is basically formed by the following cereal cultures: wheat (Triticum aestivum), barley (Hordeum vulgare), oat (Avena saliva) and triticale. Rye is applied in the limited quantity in pig feeding despite all its advantages: large areas of cultivation, stable yielding capacity, low requirements to growing conditions, possibility to obtain ecologically clean production, low prime cost of grain. Rye in swine diets forms viscous solutions which break digestion process, worsen their fixation and accordingly reduce animal weight gain. Also, it was determined that rye grain had high quantity of pentosans (non-starch polysaccharides) which suppress the overall digestibility and accessibility of proteins. One of the methods of decreasing the negative influence of anti-nutritional properties of rye on pig organism and improving its digestibility is the application of fodder enzyme additives. In course of the realized investigation there was analyzed the influence of foreign fodder additives on rye-containing (Sk-21 – 10% and SK-26 – 20%) diets in swine rations. The following enzyme additives were analyzed: Rovabio TM Excel (France); Finase TM (Germany); Avizyme and Porzyme 8100 TM (United Kingdom). Application of enzyme additives Avizyme, Rovabio and Finase in mixed fodders containing rye (SK-21 - 10% of rye) for pigs at the age of 50-107 days made it possible to increase live weight on 16,8-21,7% and lower expenses for forages (fodder units) per 1kg of weight gain on - 12,3-18,2%. Intensity of live weight gain from 50-day up to 190-days age was the following: in a control group -80,8 kg, in the first experimental group fed with Rovabio - 88,6 kg, in the second experimental group fed with Avizyme - 89,7 kg, in the third experimental group fed with Finase - 84,6 kg. Research results showed that enzymes Avizyme and Rovabio rendered the highest influence on mixed fodders containing rye (SK-21 - 10% of rye and SK-26 - 20% of rye)

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%