In the conditions of the Republic of Belarus the was studied the age-specific dynamics of content of total lipids, triglycerides, total cholesterol, phospholipids, total iron and catalase activity in spleen of broiler chicken during the incubation period (1-46 days). The content of total lipids, total cholesterol, and phospholipids was at maximal level at one day-old age, and gradually lowered by the end of growing period. The amount of total iron in ontogeny increased till the 30 day-old age and a bit lowered by the end of growing period. In broilers with lower live weight the iron content in spleen was lower during the whole growing period. The catalase activity had a wave-like character and depended on prophylactic vaccinations undertaken and the amount of lipids in tissues.

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.

There was studied a preventive efficiency of complex additive Felutsen and its influences on the metabolic status of pregnant dry cows and the indicators characterizing animal yield, received from these cows. Felutsen is the carbon-vitamin-mineral additive containing a complex of carbohydrates, vitamins A, D, Е, micro-and macro elements (sodium, chlorine, calcium (Сa), phosphorus, magnesium (Mg), sulfurs, Cu, Zn, Co, Mn, selenium, iodine) in number of 300g/animal. At cows after calving metabolism disorders are caused by disorders of liver functional activity. Application of complex additive Felutsen to pregnant dry cow allows to carry out successfully preventive maintenance of metabolism disorders, including micro-and macro element metabolism. Use of Felutsen is effective preventive maintenance of pre-natal development disorders of calves, developments of oligotrophy in the postnatal period, raises safety and growth intensity of increase. The most considerable distinctions are revealed in group of cows at which the additive was applied in the form of a briquette to which there was an easy approach. In the tabular form the indicators characterizing the basic metabolic processes, an exchange of macro elements and microelements at cows are presented at application of this additive, and also body weight, disease and safety of the calves received from cows control and test groups. | Целью работы стало изучение профилактической эффективности комплексной добавки Фелуцен и её влияния на метаболический статус стельных сухостойных коров и показатели, характеризующие приплод, получаемый от этих коров. Фелуцен – это углеродно-витаминно-минеральная добавка, содержащая комплекс углеводов, витаминов А, Д, Е, микро- и макроэлементов (натрий, хлор, кальций (Сa), фосфор (Р), магний (Mg), серу, Cu, Zn, Co, Mn, селен, йод) в количестве 300 г/животное. У коров после отёла нарушения метаболизма обуславливаются нарушениями функциональной активности печени. Применение комплексной добавки Фелуцен стельным сухостойным коровам позволяет успешно проводить профилактику обменных нарушений, в том числе и обмена макро- и микроэлементов. Использование Фелуцена является эффективной профилактикой нарушений внутриутробного развития телят, развития гипотрофии в постнатальный период, повышает сохранность и интенсивность роста приплода. Наиболее значительные различия выявлены в группе коров, у которых добавка применялась в виде брикета, к которому был свободный доступ. В табличной форме представлены показатели, характеризующие основные метаболические процессы, обмен макро- и микроэлементов у коров при применении этой добавки, а также живую массу, заболеваемость и сохранность телят, полученных от коров контрольной и опытных групп.

In the conditions of the Republic of Belarus there was determined the parasitizing influence of Oesophagostomum and their larvae on a metabolism of experimentally infested animals. In course of the study there were generated experimental and control groups of two-month old piglets. Animals of the experimental group were infested in a dose of 15000 invasion larvae per one kg of body weight. Animals of the control group were not infested. Infestation was realized through a mouth with invasion larvae with wet forage. Invasion larvae received by cultivation of excrement tests from infested pigs at temperature of 24 deg C. As a result of the realized research it was established, that Oesophagostomum invasion rendered a substantial influence on the experimental animals. At bimestrious pigs after the experimental infection with Oesophagostomum larvae there were stated the following changes: the disease on 4-30th day was characterized by frustration of function of a gastroenteric path - diarrhea, fever, anaemia, and in the subsequent - stagnation and juvenilism of animals. Oesophagostomum in a host organism caused the pathological changes of haemotological and biochemical blood value which were expressed in quantity decrease of erythrocytes, concentration of haemoglobin, leucocytosis. Eosinophilia was observed in a leukogram. In blood serum there was stated the lowering of crude protein and its fractions content; gradually, but authentically there was noted the increasing of activity serum glutamic oxalacetic transaminase and glutamic-pyruvic transaminase. Bactericidal and lysozymic activity of blood serum decreased. Activity of alkaline phosphatase increased.

The research directed on perfection of a cattle protein food system, taking into account its fractional structure, and also establishment of objective indicators of an estimation of forage protein nutrient density, have great value. It is established, that for young growth of cattle of 4-6 months of age the optimum parity of decomposable and un-decomposable protein in rations corresponds to size 68:32, allowed to raise digestibility of nutrients on 3-4%, nitrogen adjournment in an organism of animals on 10% and daily average a gain on 4% in comparison with parity 80:20. The optimum parity of fractional structure of protein makes positive impact on oxidation-reduction processes in organism to what testifies morphological-biochemical structure of blood. Thus concentration of crude protein raises on 1,7%, urea quantity decreases on 23%. The least cost price of a gain has appeared in group with a parity of decomposable and un-decomposable protein in rations 68:32, or it is better on 4,4% than an indicator of group with a parity 80:20%

Nowadays in connection with an interdiction for antibiotics use in animal feeding it is very actual to work out and apply new forms of probiotic preparations which should be as ecologically safe and harmless both to people and animal products. Probiotics make it possible to improve the digestibility of nutritive substances of forages, normalize metabolism, enrich with biologically active substances that promotes the increasing of their productivity. In the Republic of Belarus the probiotics are produced in the obviously insufficient quantity that creates problems of young stock livability. Influence of application of Akozil and Sublicin probiotics in diets of suckling calves on biochemical parameters of blood serum was analysed. It was stated that use of the analysed probiotics made it possible to decrease the level of urea and total cholesterol, to increase of the total protein content in blood serum of the experimental calves. There was noted the increasing of glucose level in blood serum of calves fed with Akozil. There was marked the tendency of more optimal level of calcium and phosphorus in calves having Sublicin in their diets. The obtained results testified the normalization of metabolic processes taking place in calves which were fed by the mentioned above probiotics

In the conditions of the Republic of Belarus there was realized a morphological analysis of pectoral and leg muscles of broiler chickens of cross Cobb-500 in the process of administration of metabolic activator Catosal. Research results showed the positive influence of catosal on the myogenesis: diameter of muscle fiber, the amount of bigger diameter muscles fibers in the first order strand and homogeneity of muscle strands. Under the influence of Catosal preparation there was stated the increasing of the amount of muscle tissue in pectoral and leg parts of chicken carcass. | Приведены данные морфологических исследований грудных и ножных мышц цыплят-бройлеров кросса Кобб-500 при применении активатора метаболизма катозал. Установлено, что катозал активизирует миогенез за счет увеличения диаметра мышечных волокон, содержания в пучках первого порядка мышечных волокон большей толщины, а также большей однородности мышечных пусков. Под действием препарата происходит увеличение содержания мышечной ткани как в грудной части тушки, так и в окороках.

In the conditions of the Republic of Belarus there were determined types of transferrins of 46-day old broiler chickens and their relation with indexes characterizing ferrum transport fund. In broilers of Smena-2 cross there were stated four transferrin phenotypes, which revealed at a electrophoregram in a form of two fractions with various mobility and intensity. The quantity of the found out phenotypes should be considered as a minimum one because it was possible to find out the infrequent forms only after realization of a very big number of research studies (for example, occurrence of some phenotypes can be 1:1000 and even lower). Perfection of electrophoresis techniques or application of other carriers (for example, polyacrylamide gel) can also increase a number of phenotypes owing to high resolving power and division of homogeneous transferrin fraction into several sub-factions. The type of transferrin actually did not render influence on the content of haemin proteins, while the indices of ferrum transport fund showed out such kind of dependence. Taking into account that total iron binding capacity (TIBC) was caused by transferrin presence in blood serum, the distinction in this indicator characterized both the transferrin content, and its transport possibilities in relation to iron. The highest content of total iron and TIBC was observed at a slow phenotype of CD tranferrin type (formed by fractions with the least mobility). Fast type of tranferrin АВ (formed by the most mobile fractions) had high enough content of the totaliron but possessed the least iron-binding ability that specifies to the worst performance capabilities of transportation of iron ions. Taking into consideration the transferrin value in formation of antibacterial immunity, it is possible to assume, that broilers with phenotype СD should be more resistant to infections.

In the conditions of the Republic of Belarus there was analyzed the efficiency of application of a probiotic lactic casein feed additive DKM which was developed in the Institute of Microbiology of the National Academy of Sciences of Belarus. The analyzed additive contained specially selected lactic-acid bacteria with a high bioartificial potential of metabolites. In course of the experiment there was studied the consumption of fodders (milk; oats; mixed fodders) by experimental calves; dynamics of live weight gain in the beginning and at the end of the experiment; average daily weight gain. Also, there were analyzed the background indexes of blood serum of calves, as well as the indexes of blood serum of calves in a month after application of DKM additive. Research results showed that application of the feed additive DKM promoted better palatability and use of fodders and rendered positive influence on animal productivity. Also, there was marked the normalization of metabolism that was proved y the laboratory tests of blood serum.

Development of new compositions of premixes for cows with milk yield of 4-5 thousands kg per lactation depending on lactation stage and pregnancy was realized in the conditions of the Republic of Belarus. Efficiency of application of premixes in comparison with the standard ones was estimated. Experiment was realized by an example of 3 groups of cows of white-and-black breed; experimental period included beginning milking period (90 days) and the main lactation period (142 days). Cows of the first control group were given premix P60-6M with combined feed. Animals of the second group were fed with premixes created on the basis of carotene and microelements content. Cows of the third group were given premixes in accordance with recommended standards. The refined standards of cow vitamin and trace elements consumption were presented. Formulas of premixes for high-producing cows were presented. The research results showed that the developed formulas corresponded to the physiological needs and their application influenced on metabolism and milk producing ability. Application of experimental premixes made it possible to increase the digestibility of nutritive substancesoin 2,3-7,5%. Application of vitamins and trace elements in heightened doses (on 10-30%) caused the increasing of their uptake and increasing of cuprum, zinc, manganese and cobalt content in blood on 11,6-40,8%