Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) of Rocky Mountain elk in North America. Recent studies suggest that tissue and blood mineral levels may be valuable in assessing TSE infection in sheep and cattle. The objectives of this study were to examine baseline levels of copper, manganese, magnesium, zinc, selenium, and molybdenum in the brains of Rocky Mountain elk with differing prion genotypes and to assess the association of mineral levels with CWD infection. Elk with leucine at prion position 132 had significantly lower magnesium levels than elk with 2 copies of methionine. Chronic wasting disease-positive elk had significantly lower magnesium than control elk. The incorporation of manganese levels in addition to magnesium significantly refined explanatory ability, even though manganese alone was not significantly associated with CWD. This study demonstrated that mineral analysis may provide an additional disease correlate for assessing CWD risk, particularly in conjunction with genotype.

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.

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.

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.