In the conditions of the Republic of Belarus there was determined of a dose of input and efficiency of feeding with rape oil cake and protein meal produced on the basis of a new rape (Brassica napus) variety Yavar as a part of a mixed fodder KR-2 in diets of young stock of cattle. Rape oil cake and protein meal with the content of 1,4-1,9% glucosinolates and 27-30 mcM per 1 kg of a dry matter of erucidic acid can be included into composition of the mixed fodder КR-2 for bull calves in a dose up to 20% on weight. Feeding with the mixed fodders КR-2 with inclusion of rape oil cake and protein meal made it possible to receive daily average weight gain of calves at a level of 827-906 gram at expenses of forages of 5,4-5,9 forage units per 1 kilogram of a weight gain. It was caused by cheaper rape forages. In course of the study there was analyzed the chemical composition of rape oil cake and protein meal; indexes of rumen digestion of experimental bull calves; morphological and biochemical blood structure; changes of body weight; daily average weight gain and expenses for forages.

In the conditions of the Republic of Belarus there was determined the genetic structure of population of breeding boars, sows, replacement and crossbred stores in accordance with RYR1 gene which was connected with stress resistance. Also, there was analyzed the influence of genetic polymorphism of this gene on meat productivity. In course of the study there was presented a genetic structure of breeds according to gene loci RYR1. There was analyzed the frequency of occurrence of alleles and genotypes in accodance with gene loci RYR1 of breeding boars and replacement stores of different lines. There were showed the indexes of meat productivity and acid capacity of purebred and crossbred stores with different RYR1 gene genotypes. As a result of study there was revealed a rather high level of presence of allele RYR**n in all sex and age specific groups of Belarusian meaty breed (21%) and crossbred stores of Large white x Belarusian meaty breeds (40%). But in the experimental group of three-breed cross breeds (Large white x Belarusian meaty) x Duroc there was not stated the presence of allele of malignant hyperthermia. High level of RYR**n allele presence in populations of meaty breeds and their crossbreeds proved the necessity of obligatory genetic control of pedigree as well as imported animals by means of DNA diagnostic.

In the conditions of the Republic of Belarus there was realized an ecological monitoring of sources of water supply in the conditions of a swine breeding complex and adjoining settlements. There was studied the influence of a large swine breeding complex on water quality of closed type water sources. There was marked a microbial contamination of water depending on remoteness of animal breeding object and season of a year. There were determined the seasonal changes of physical properties, chemical and bacteriological composition of water used for swine breeding. There were noted changes in water quality in the process of its flow from the point of water inlet up to the place of its consumption. Results of influence of improved water on piglets were presented. There was studied the possibility of improvement of water quality by means of its treatment with solution of potassium hypermanganate (0,01%) which made it possible to increase average daily live weight gain of piglets. In course of the study there was realized the analysis of protein spectrum of blood serum of piglets; dynamics of body weight and average daily weight gain of experimental piglets.

In the conditions of the Republic of Belarus there was analyzed the influence of diets with different ratio of degradable and by-pass proteins on morphological and biochemical blood composition and productivity of bulls of black-and-white breed. In course of the study there was analyzed the average feeding diet of young stock of cattle in accordance with actually eaten fodders; morphological and biochemical blood indexes; live weight and average daily weight gain; results of a control slaughter. Research results showed the feeding at the finishing period of fattening-off with different ratios of degradable and by-pass proteins in ratio 60-65:40-35 made it possible to obtain 1049-1078 grams of live weight gain of bulls per day in the conditions of fodder expenses of 8,22-8,40 fodder units per 1 kilogram of weight gain. As a result the energy of weight gain was 20,1-21,2 mJ. Conversion of metabolizable energy at weight gain stage was at the level 20,4-21,8%. Expenses of metabolizable energy per 1 mJ at weight gain were 4,83-5,05 mJ, and prime cost of body weight gain lowered on 5% in comparison with control.

In the conditions of the Republic of Belarus there was analyzed the efficiency of application of a whole milk substitute Biomilk-11 and feed additive SFDK-1 (biologically active enzymatic feed additive) for breeding of young stock of cattle, by an example of calves of black-and-white breed. In course of the study there was analyzed the composition of the feed additive SFDK-1 (weight fraction of dry matter; weight fraction of protein; content of amine nitrogen; cellulose fiber activity) as well as the physical and chemical indexes of the whole milk substitute Biomilk-11 (moistness; crude protein; crude fat; crude fibre). There were presented indexes of live weight gain of experimental and control calves as well as the dynamics of average daily weight gains in experimental group. Research results proved the efficiency of application of both additive for calves feeding.

In the conditions of the Republic of Belarus there was determined the efficiency of application of different levels of vitamins and trace elements in feeding of servicing bulls. In course of the study there was analyzed the influence of different levels of supply of servicing bulls with vitamins A, D, E and trace elements (copper; zinc; manganese; iron; cobalt; selenium) on their reproductive ability. On the basis of the experiment there was calculated the economic efficiency of application of the developed vitamin and mineral additive. Research results showed that application of the developed protein and mineral additive in diets of servicing bulls in winter and summer periods made it possible to increase the ejaculate volume on 7,4% and 12,4% (P less than 0,05), sperm activity on 6,7 % (P less than 0,05) and 7,3% (P less than 0,01), concentration of spermium in ejaculate on 6,3% and 7,8% (P less than 0,05). Also, it promoted the lowering of percentage of defective sperm doses.

There were presented data of morphological analysis of blood and tissues from a place of vaccine administration and organs of immune system (thymus and lien) of rats vaccinated against a canicola fever of pigs by a produced in the Republic of Belarus vaccine containing in its structure various adjuvants. The vaccination was realized in combination with immunostimulative drugs. Level of specific antibodies of rats and rabbits after immunization with the analyzed preparations as well as with and without immunostimulative drugs were analysed.

In the conditions of the Republic of Belarus there were analyzed the peculiar features of morphology of bursa of Fabricius of turkeys broad-breasted white turkeys at the stage of postnatal ontogenesis. Research results showed that postnatal ontogenesis of bursa of Fabricius of turkeys developed irregularly with preservation of organ up to 220 days. At turkeys in 300-day old age the organ preserved only in 45% of bird units. Form, colour and consistency of bursa of Fabricius depended on bird age. The absolute weight of the organ increased up to 220 days. The relative weight was maximum at 20-day old age. The sexual peculiar features of the organ morphology were insignificant; they revealed after the beginning of sexual maturity and expressed by some difference in weight and linear dimensions.

In the conditions of the Republic of Belarus there was determined the influence of nutritional medium composition on pathogenic properties of leptospirosis bacteria, by an example of 6 pathogenic strains: Leptospira pomona; Leptospira tarassovi; Leptospira grippothyphosa; Leptospira icterrohaemorragia; Leptospira conicola; Leptospira hardjo. During the study there were used the following media: serum-supplemented vitaminized medium on the basis of buck serum; serum-supplemented medium with a growth factor; serum-supplemented vitaminized medium with antlbody biosynthesis growth factor; semisynthetic Russel's medium. According to the results of realized studies there was developed a correlation between terms of leptospirosis bacteria survivability in laboratory animals depending on cultivation medium. In course of the study there were analyzed terms of Leptospira persistence in guinea pigs.

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.