In given article natural resistance of geese during the spring-and-summer period is considered at inclusion in a diet coenzyme B12. Namely, dynamics bactericidal, lysozyme activity of blood of geese, dynamics of phagocytosis activity, the general fiber in blood whey, dynamics of fiber gamma-globuline fraction and reliability of distinction between groups is resulted

Application in diets of producing bulls of the increased doses of vitamins and trace elements promotes the increasing of indexes of their reproductive ability on 6,3-12,4% and natural resistance on 3,3-8,8% during the winter and summer periods, and also allows to receive profit on 1 ruble of expenses 3,7 rubles

In the conditions of biogeochemical zone of the Republic of Belarus the most important role in mineral metabolism is played by such major mineral elements as calcium, magnesium, phosphorus, potassium and trace elements - cobalt, cupper, iron, iodine, zinc, manganese, and selenium. Based on the above there was determined the interrelation between the content of these minerals in fodder and blood of milking and dry pregnant cows. As a result of realized study it was found out that the content of major mineral elements and trace elements in fodder did not always correspond to their level in blood. In the conditions of insufficient supply of Ca, F, Mg, K, Fe, Си and Co in cow diets, the level of potassium in blood was lower standard and the other analysed minerals were within the standard limits. There was stated the direct correlation relationship between the level of some biochemical indices and content of mineral substances in cow diets. Positive correlation was stated between the content of calcium and magnesium and cholesterin level in blood

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

Analysis of the efficiency of application of fermented milk supplementary feed DKM (Belarus) produced on the basis of bacteria strain Lactobacilus acidophilus 55/06 in calve diets was realized in the conditions of the Republic of Belarus. Influence of feeding with acidified with the trial milk additive on forage palatability, biochemical blood structure and calve productivity was studied; economic efficiency of DKM use for processing of whole milk and its use in rations of calves was defined. Experimental batches of DKM fermented milk supplementary feed were produced at Grodno Medical Preparations Plant (Belarus). It was issued in the sterile corked polyethylene 5, 10 and 20 liter bottles or canisters. The fermented milk supplementary feed DKM could be stored at the temperature from 0 deg С up to 15 deg С. Shelf-life – 3 months from the moment of production. The additive represents the homogeneous mass of viscous consistence of cream color of various shades with a sour-milk smell. The carried out economic calculations showed, that as a result of growing capacity increase it animals of a trial group and reception of an additional total live weight gain there was stated the 6,5% decrease of expenses for fodder unit production in the experimental group. However, due to a high cost of acidified milk the cost of fodder unit in trial group was on 6,8% higher. As a result, the cost price of 1 kg weight gain in trial group (despite high additional weight gains) was stated at the level of control group. Application of fermented milk supplementary feed DKM in calve diets made it possible to lower calf disease incidence and to increase calf productivity on 11,8% without increasing the cost price of production

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%

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%

Studying of influence of various levels of selenium on growth, protein structure of blood serum, natural resistance, and reproductive performance of pedigree bull-calves was realized in the conditions of the Republic of Belarus. It was established, that feeding with an optimum dose of selenium (0,4 mg per 1 kg of dry matter) in rations of replacement bull-calves during the raising period promoted the increasing of daily average weight gain on 6,8%, indexes of natural resistance - on 0,5-13,9%, and sperm production quality - on 4,5-27,3%. In the conditions of optimization of selenium level of in diets the protein structure of blood serum of replacement bull-calves exceeded the similar index at control animals by the crude protein index - on 8,3 (Р less than 0,05), by albumine and alpha globulin -on 2,2% and 1,6%, respectively. Application of selenium in dose of 0,4 mg per 1 kg of dry matter made it possible to increase the indexes of natural resistance on 0,5-13,9%. Increase of selenium dose up to 0,4 mg per 1 kg of dry matter in made it possible to increase the quantity and quality of sperm of bull-calves, that was proved by the increasing of ejaculate volume on 4,5%, concentration of male germ cells in ejaculate – on 15,7% (Р less than 0,05) and male germ cells activity - on 7,3% (Р less than 0,001)

In the conditions of the Republic of Belarus there were analyzed the efficiency of 13-18-month old young stock of cattle bred for meat in the conditions of various energy value nutrition levels with the determination of nutrients intake of a diet. It was established that use of rations with various level of metabolic energy and protein breakage rendered the positive influence on nutrient digestibility of rations. This made it possible to improve the digestibility of dry and organic substances, nitrogen-free extractive substances and fibre at the bull calves which were fed with 63% of cleavable protein, as well as to increase the metabolic energy up to 10% in the ration, surpassing the control indexes respectively on 3.1; 2.5; 2.8; and 2.9 items. Adjournment from the acquired nitrogen considerably increased and made up to 64-70%. Productivity of fattening young cattle stock made it possible to obtain 977.7-1011.0 gram of live weight gain. As a result, the growth energy was stated at the level of 15,90-17,33 МJ in the conditions of conversion of metabolic energy into growth of 13,81-14,26% and expenses of metabolic energy of the ration per 1 MJ in live weight gain of 4,72-5,46 MJ.

Scientific experiments on determination of the optimal doses kizelgur for import substitution of shells in poultry diets was realized in the conditions of the Republic of Belarusby an example of 4 groups of laying hens of Khajseks korichnevyj cross. Hens of the first (controlled) group were given full ration applied at the tested poultry farm which included 5% of shells. Hens of the other three experimental groups were given complete feedstuffs with inclusion of mineral feed kizelgur: hens of the second group – in dose 2% out of dry matter mass; third group - 3%; for the fourth group - 4%. The research results showed that application of mineral feed additive kizelgur increased hen productivity in experimental groups on 2,8%; 5,9%; 7,2%, respectively. In the experimental groups there was an increasing of egg yields on 2,8%; 5,9%; 7,2%, respectively. The best indexes of poultry livability were stated in the third group (on 5,5% higher than in control). The similar tendency was stated in course of analysis of egg weight, shell thickness and calcium content of shell. Kizelgur application led to increasing of egg mass in tested groups: on 0,46% (2 group), 1,6% (3 group) and 2,4 % (4 group). At the age of 340 days shell thickness in experimental groups was on higher 3,3% (2 group), 0,7% (3 group) and 8,7 % (4 group) than in control. The analyzed additive increased the natural resistance of hens that was proved by indexes of bacterial growth-inhibitory activity of blood serum and lysozyme activity. There noted tendency of total protein increasing. Studying of immunological indexes showed that they were the most evident in the fourth experimental group