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.

The research was realized by an example on 30 chickens aged 1, 10, 20, 30 60-days old, and 10 hens: 4-months, one-year-old and 2-year-old in the conditions of the Republic of Belarus. All poultry stock was maintained in the conditions of industrial production at the Gorodokskaya Poultry Farm of Vitebsk region (Belarus). As a result of the study there was revealed a certain pattern of variation of a quantity of active forms of enzymes in organs chickens of different age. Application of histochemical methods made it possible to reveal different levels of metabolic processes in cellular elements of thyroid gland, which demonstrated the habit of formation and functioning of the organ at different stages of postnatal ontogenesis in hens. Coefficients of acid phosphatase activity in thyrocytes of thyroid gland of hens and indexes of alkaline phosphatase activity in secretion forming cells were analyzed. | Исследование провели на 30 цыплятах в возрасте 1-, 10-, 20-, 30- 60-дней, и 10 курах: 4-месячные молодки, годовалые и 2-летние особи. Все поголовье птицы содержалось в условиях промышленного производства на Городокской птицефабрике Витебской области. В результаты исследований установлена определенная закономерность изменения количества активных форм ферментов в органах птиц разного возраста. Использование гистохимических методов позволило выявить разные уровни метаболических процессов в клеточных элементах щитовидной железы, которые демонстрируют характер становления и функционирования органа на разных этапах постнатального онтогенеза кур. В табличной форме представлены коэффициенты активности кислой фосфатазы в тироцитах щитовидной железы кур и показатели активности щелочной фосфатазы в секретообразующих клетках.

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 was determined the influence of multi-enzymatic veterinary drug preparations Vitazim (contained a complex of enzymes of carbohydrases: xilanase; cellulose; beta-glucanase) and Ehkosim (universal multi-enzymatic complex: beta-glucanase; endo-xilase; and cellulase) on microbial composition of intestinal bacterial population. Research was realized by an example of layer hens of four-linear cross Highsex white at the age of 34-51 weeks. Regimens of administration of the analyzed preparations were presented. Research results showed promoted the development of the regenerative process of physiological media in intestines of poultry which was necessary for subsisting of normal flora of pathogenic bacteria. The studied preparations Vitazim and Ehkosim can be applied for the preventive treatment and therapy of intestinal dysbacteriosis, normalization of its microbial flora, as well as for the antibacterial therapy.

In the conditions of the Republic of Belarus there was realized a comparative studying of immune reactivity of broiler chickens immunized against Marek's disease by means of vaccines of Russian production. In course of the study it was established, that in broiler chickens vaccinated against Marek's disease (by means of cultural dry viral vaccine on the basis a virus of herpes of turkeys FS-126 and by liquid bivalent cultural virus vaccine Bimarek on the basis of strains of a herpes virus of turkeys and a herpes virus of hens) the revealed morphological changes in immune system organs of did not essentially differ and testified to the development of intense postvaccinal immunity. Economic efficiency of immunization of broiler chicken against Marek's disease under production conditions made 4,87 and 2,94 Belarusian roubles per 1 rouble of expenses, respectively. | Целью исследования явилось сравнительное изучение иммунной реактивности организма цыплят-бройлеров, иммунизированных против болезни Марека вакцинами российского производства. В ходе исследований установлено, что у цыплят-бройлеров, вакцинированных против болезни Марека культуральной сухой вирусвакциной из вируса герпеса индеек ФС-126 и жидкой бивалентной культуральной вирусвакциной Бимарек из штаммов вируса герпеса индеек и вируса герпеса кур выявленные морфологические изменения в органах иммунной системы существенно не отличаются и свидетельствуют о выработке напряженного поствакцинального иммунитета. Экономическая эффективность иммунизации цыплят против болезни Марека в производственных условиях составляет 4,87 и 2,94 рубля на 1 рубль затрат соответственно.

In the conditions of the Republic of Belarus there was studied the influence of various doses of kizelgur on metabolic processes and natural resistance of poultry by an example of lying hens. Use of the mineral additive rendered the positive influence on protein, carbohydrate, lipidic and mineral metabolism in hens. It was marked that in blood the content there was an increasing of crude protein on 11,5-11,7% (Р less than 0,05), crude lipids - on 1,9-5,3%, glucose - on 25,1-54,6% (Р less than 0,01), calcium - on 0,8-12,4%, phosphorus - on 8,9-15,9%, iron - on 9,2-24,6% (Р less than 0,01) and magnesium - on 9,3-21,6%. The laying hens which were fed with the mineral kizelgur additive were characterized by better resistance reactions. Bactericidal activity of blood serum of the experimental hens was higher on 2,7-15,3% (Р less than 0,01), lysozymic activity - on 1,3 22,5% (Р less than 0,05).

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.