In the conditions of the Republic of Belarus there was studied the activity of alaninaminotranspherase (AIT) and aspartate aminotransferases (AsT), alkaline phosphatase, lactic dehydrogenase, cholinesterase, alpha amylase in blood serum, liver and pancreas of 130-158-day old replacement chicks vaccinated against Newcastle disease. Research results showed that the most essential changes were observed from such enzymes, as AsT and AIT. Increasing of AIT activity in a liver, pancreas and blood serum of immunized hens was stated on the seventh day after vaccine administration. Character of changes can testify both the increasing of synthesis of the mentioned enzymes, and also their posttransmitting activation which took place due to intensification of transamination processes. Changes of activity of alkaline phosphatase, cholinesterase and alpha amylase were the most expressed on the 14th and 21st days of research. It was possible to assume, that there was a stimulation of synthetic function of hepatocytes under the influence of the vaccine. It was possibly the decreasing of enzymatic functions pancreas.

In the conditions of the Republic of Belarus there were studied the influence of different levels of glucosinolates of rape (Brassica napus) seeds on metabolic processes and productive qualities of lying hens for the determination of an optimal dose of administration into their diets of ground rape seeds of the national Belarusian selection in spite of extraction cakes of other crops. Research results showed that addition into mixed fodder of 8-13% of rape seeds increase in their share in a lying hen diets caused the decreasing of the basic zootechnical indexes and did not render essential influence on production quality. However, introduction 6% rapeseeds into diets of lying hens of commercial stock instead of oil-seed meal of other crops did not render essential negative influence on productive indexes and production quality. Feeding of 6% of rapeseeds in spite of oil-seed meal of other crops in course of ten months of technological use of poultry caused the increasing of total yield of eggs on 2,9%, egg production - on 1,8%, average weight of eggs - on 1,7%. Also, it made it possible to reduce the daily consumption of forage on 2,6%, forage expenditures per 10 eggs - on 5,5% and per kilogram of egg weight - on 5,8%. The obtained results assume the possibility of inclusion into lying hens diets of 6% milled rapeseeds of national selection with a level of glucosinolates up to 44,7 mkmol/g.

Analysis of the optimal scheme of doses and rates of combined administration of probiotic Dialakt and immunostimulant Alveozan was realized in the conditions of the Republic of Belarus by the example of 1500 broiler chickens of cross Kobb- 500. Chickens of the first (controlled) group were given only total ration, balanced with the main nutrients. For the chickens of the second group were administrated with immunostimulant Alveozan with water starting from one day old age, every day in dose of 10 mkg/kg of body weight once a day in course of 5 days successively and with 7 days interval till the end of growing period; and probiotic Dialakt was administrated with water in dose of 0,1-0,2 ml/head (10,0-20,0 mln microbial bodies) starting from one day old age, once a day in course of 5 days successively and with 6 and 14 days intervals till the end of growing period. Chickens of the third group were administrated Alveozan in dose of 10 mkg/kg of body weight with drinking water once a day in course of 5 days with 10 days interval till the end of growing period; and Dialakt in dose of 0,1-0,2 ml/head with drinking water starting from one day old age, every day in course of 5 days with 6 and 14 days interval till the end of growing period. The research results showed the following optimal regime of complex application of the analyzed preparations: immunostimulant Dialakt - in dose of 0,1-0,2 ml/head with drinking water starting from one day old age, once a day in course of 3 days successively with 6 and 14 days intervals till the end of growing period; and immunostimulant Alveozan - in doze of 10 mkg/kg of body weight with drinking water once a day in course of 5 days with 10 days interval till the end of growing period. Complex application of Dialakt and Alveozan promoted the increasing of organometric indexes, specific volume and size of thymus in 1,5-1,8 times (P less than 0,01), Fabritsiya bursa - in 2 times (P less than 0,01) and lien - on 11,1% (P less than 0,05)

Investigation of influence of complex probiotic preparation Laktimet obtained by means of cultivation of bifidus bacteria and lactic acid bacillus on morphological indexes of pancreatic gland of laying hens was realized in the conditions of the Republic of Belarus. Two groups of laying hens of 121-130 days old were used in the experiment. The experimental hens were given probiotic Laktimet with water in dose of 1 ml/head every day in 4 cycles during 7 days and with 7 days intervals. Total condition, dynamics of body weight, and egg production were estimated. Research results showed that body weight of experimental hens increased on 6,4 % on the 10-th day; on 12,1% - on the 24-th day; on 6% - on the 40-th day; and 7,5% - on the 50-th day of experiment. Pancreas weight of experimental hens increased on 4-9%. Acinus size increased on 11%. Morphological indexes in exocrine pancreatic cells showed that altitude of basal pole increased on 3-7%. Application of probiotic Laktimet rendered positive influence on laying hens that was evident in increasing of their productivity (there was an increasing of live weight on 4-8%, and egg-laying capacity – on 18-33%). The positive dynamics of the majority of morphofunctional indexes of exocrinous and endocrine parts of pancreatic gland proved its significant role in maintenance of general state of laying hens and metabolic processes

Application of antiviral preparation Mixoferon for poultry is studied. It is established, that Mixoferon application does not influence negatively on organism of hens, increases intensivity of protein metabolism, including the maintenance of antibodies in blood whey. Mixoferon in dozes of 2,5 ml (500000 МЕ), 1,5 ml (300000 МЕ), 0,5 ml (100000 МЕ) can be used for preventive maintenance and therapy of virus infections of hens

Application zoned bare-grained oats grades in a diet of chickens and hens-layers of egg breeds makes positive impact on efficiency of a bird, forage conversion, reduces expenses of forages for manufacture of eggs that allows to receive additional profit. The maximum norm – 40 % bare-grained oats in mixed fodders of hens is defined

Into the programme hen selection of Belarus Autoseksnyj cross there was introduced the indeks of the so-called quality of eggs which is defined by removal defective on quality of a shell of eggs in 30 and 52-week age. The size of variability of an indicator of 16,0-25,4% and hehtability 0,3-0,4 allows to lead selection on increase in an exit of qualitative eggs. Influence on quality of eggs with defects of a shell of age of hens, intensity eggs, weights of eggs, a linear accessory is established

In the conditions of the Republic of Belarus there was studied the influence of various doses of dolomite on productivity, egg quality and a mineral metabolism of laying hens. The research was realized by an example of laying hens of Highsex Brown. The experimental hens at the age of 250 days old were divided into 4 groups on 60 heads in each by means of analog method. Laying hens of the first (control) group were fed with a basic diet including 5% of a soya cake (cockle-shell), and hens of the second, third and fourth (experimental) groups instead of a soya cake were fed with a mixed fodder with addition of a mineral additive of dolomite. Hens of the second group were fed with the additive at a rate of 2%, the third group - 3%, and the fourth group - at a rate of 5% of weight of dry matter of forage. During the experiments there were maintained optimum parameters of microclimate, recommended temperature and light regimes and a sufficient ultra-violet irradiation. As a result of the realized research it was established, that use of the mineral dolomite additive in feeding of laying hens proved to be possible as a substitute of an expensive import cockleshell. Use of various doses of dolomite promoted improvement of mineral metabolism, increasing of productivity and improvement of egg quality of laying hens.

In the conditions of the Republic of Belarus there was analyzed the efficiency of application multi-enzyme preparations (drugs) Ehkozim (contained beta-glucanases; endo-xilanase; cellulose) and Vitazim (contained complex of enzymatic carbohydrases: xylanase; cellulose; beta-glucanases) in diets of lying hens. Vitazim was applied for destruction of complex structures: dietary fibre, protein, starch. Ehkozim was applied for albuminolysis of the main nonstarch polysaccharides of fodders. It was established that application of preparations in feeding of lying hens promoted the increasing of biological value of poultry meat, and prove to be economically expedient. Poultry meat of analyzed samples in accordance with physical, chemical and bacteriological indices, as well as in accordance with biological value and harmlessness was not worse than meat of control samples. As a result of the realized bacteriological research of all experimental samples of meat and internal organs there were not stated microorganisms Е. coli, S. aureus, bacteria of sort Proteus, B. сеreus and sulfate-reducing clostridium, salmonellas.

Scientific and production examination of feed additive Semerik-Vita containing iodine and selenium was realized in the conditions of the Republic of Belarus by studying of its influence on production and economic indexes of laying hens and their products, as well as by studying of its influence on clinical state and biochemical blood indexes of poultry. Research results showed that application of feed additive Semerik-Vita made it possible to increase of egg producing ability intensity on 1,8 %, egg yield - on 2,4 % in the conditions of lowering of feeding expenses on 1,4 %. Application of the analyzed feed additive made it possible to obtain a new kind of eggs fortified with iodine, selenium, beta-carotene and vitamins (A, E, C, PP, B1, B2, pantothenic acid and folic acid). In eggs of poultry of experimental group the content of selenium increased in 2,1 times, iodone - in 1,5 times, vitamin E – in 3,9 times, beta-carotene – in 1,4 times, vitamin A – in 1,3 times, pantothenic acid – in 1,2 times, vitamin C – in 1,17 times, vitamin PP – in 1,4 times, vitamin B1 – in 1,5 times, vitamin V2 – in 1,4 times, folic acid - in 1,5 times in comparison with eggs of laying hens from the control group. Research results proved that application of Semerik-Vita did not render negative effect on the clinical indexes of laying hens. It made it possible to lower the content of urea acid in 1,7 times, as well as to increase the content of triglycerides in 2 times, cholesterol - in 2,4 times, magnesium - in 1,28 times