Field efficacy of enterotoxigenic Escherichia coli-specific phage (ΦCJ19) as a feed additive was evaluated in weaning piglets. Fifty-four piglets at 3~4 weeks old were allocated in three different groups and two of them were fed with bacteriophage at different concentrations (106 PFU/kg feed and 108 PFU/kg feed, respectively) for 30 days. Body weight and feed intake were measured at 10 days interval and body condition and fecal score were inspected every day. Based on the measurement, feed conversion rate (FCR) and average daily gain (ADG) of each group during 30 days were analyzed. The analysis suggests that the bacteriophage may help the improvement of FCR and ADG at 108 PFU/kg of bacteriophage feeding group in 30 days. A result from analysis of fecal score indicates that the bacteriophage also may help to relieve the intermittent diarrhea in post-weaning stage. Those results suggest that bacteriophage might help the growth of piglets in post-weaning stage.

In the conditions of the Republic of Belarus there was realized a complex of studies of quality swine slaughter products against the background of combine applications of the albuminous-vitamin-mineral additive Immovit and an extract of hill-growing saltwort for the preventive maintenance and treatment of a toxic dystrophy of liver. Research results showed the analysed preparations did not render negative influence on quality and safety of produced meat products. Against the background of application of the albuminous-vitamin-mineral additive Immovit in combination with an extract of hill-growing saltwort there was stated the improvement of swine slaughter product quality. In products from the animals which were administrated with a complex of examined preparations there was stated an optimized moisture content, the increasing of a relative biological value of a product (101,3-103,8%), and according to the indexes of bacterial safety the experimental pork considerably surpassed the meat indexes from animals of control groups. At the same time, in slaughter animal products of control groups there were revealed coliform bacillus bacteria.

In the conditions of the Republic of Belarus there were studied the anthelminthic properties of preparative forms of elecampane (Inula helenium) (herbal infusion, tincture, liquid and dry extracts). Research results showed that the analyzed preparative forms in the administrated doses possesed high therapeutic efficiency against strongyloidosis and strongylatosis of gastroenteric path of sheep. Thus, according to results of research it was established, that the highest therapeutic effect rendered herbal infusion of elecampane in a dose of 6 ml/kg live weight once a day three days continuously; and the antiparasitic efficiency was 60%. Application of elecampane tincture in a dose of 1 ml/kg live weight once and 0,5 ml/kg of live weight twice rendered the 100% therapeutic effect. Administration of a liquid extract of elecampane in a dose of 0,2 ml/kg live of weight once and 0,1 ml/kg of live weight twice rendered 100% therapeutic effect. Application of elecampane dry extract in a dose of 30 mg/kg of live weight once and 25 mg/kg of live weight twice rendered 100% therapeutic effect.

In the conditions of the Republic of Belarus there were studied biochemical indexes of calf blood serum against the background of application of probiotic preparations Bilavet C. Results of research showed that administration of probiotic preparations from the first day till the six day and from the fourteenth day till the nineteenth day of calf life with the preventive purpose rendered the simulative influence on indexes of natural resistance, which were accompanied with the increasing of total protein quantity in blood on 2,9-5,9%, as well as the increasing of protein fractions, in particular, globulin-rich fraction on 4,2-6,4%. Administration of probiotic preparation Bilavet С to calves rendered the positive influence on blood biochemical indexes, promoted the uptaking and better accumulation of mineral substances: content of crude calcium, inorganic phosphorus, magnesium, iron increased on 15,3%, 10,5%, 13,2% and 3,6%, respectively.

In the conditions of the Republic of Belarus there was studied the interrelation between content of major nutrient elements (calcium and phosphorous) and trace elements (iron, copper, cobalt, and manganese) in forages and blood of first-calf cows at the first and last stages of lactation. Also, there were developed formulas of mixed forages and a premix for these animals. The studies were realized at the Agricultural Production Co-operative Olgovskoe of Vitebsk region (Belarus). Research of analysis of forages and state of mineral metabolismat heifers made it possible to draw following conclusions: in cow rations there was marked the deficiency of vitamin D, as well as some trace elements (cobalt and manganese) in the conditions of calcium and phosphorus excess. In spite of a high content in a calcium in diets, it was noted than in blood plasma the concentration of this element was below the standard for the majority of animals. Lack of cobalt and manganese of whole blood of cows was connected with a low level of these elements in cow diets. The surplus contents of copper in forages and blood of animals against the background low activity of ceruloplasmin the weakened antioxidant defense of heifer cows. For preventive treatment of possible hypo trace element deficiencies and metabolic disorders of heifer cows at the final stage of lactation there can be recommended the correcting of cow diets with inclusion into their composition of the developed for compound of mixed fodder and premix.

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 influence of inclusion into broiler chickens diets of probiotoc preparation Bifidoflorin zhidkij (liquid) and prediotic veterinary drug Biofon AIL on the natural resistance, hematopoiesis, growth, metabolic function, development and viability of broiler chickens. In course of the study there was analyzed the dynamics of total haemoglobin, total protein of blood serum, albumins and globulins of broiler chickens which were fed with veterinary drugs probiotoc Bifidoflorin zhidkij and prediotic Biofon AIL. Indexes of chicken viability and life weight gain were marked. Research results showed that application of the presented veterinary preparations rendered the growth promoting action, lowering of disease incidence, increasing of chicken viability, increasing of live weight gain and stimulation of metabolic processes in the most intense period of poultry growing. All these factors were expressed in highest degree after the combined application of the probiotic and prebiotic veterinary drugs.

In the conditions of the Republic of Belarus there was analyzed the efficiency of application of organic form of selenium Sel-plex in feeding of producer bulls. In course of the study there was showed the dynamics of live weight and average daily weight gain of producer bulls; blood indexes of analimals by the end of the experiment; sperm quality of experimental bulls. As a result of research it was established, that application of organic form of selenium Sel-plex in feeding of breeding bulls during the summer and winter periods in a dose of 0,4 mg/kg of dry matter of a ration promoted the increasing of daily average live weight gain on 6,4-8,1%, improvement of morphological and biochemical blood structure, increasing of indices of natural resistance on 0,5-6,1% and sperm production quality - on 7,3-28,0%.

In the conditions of the Republic of Belarus there was realized a scientific and economic experiment on studying the influence of a multi-enzyme feed additive on productivity, viability, growth and development of calves. The multi-enzyme additive contained in its formula xilanaza; glucanase; cellulose; and dolomite (as a filling agent). It was determined that young growth of cattle which were fed with the multi-enzyme additive in dose 1 gram per 6 kilogram of milk by the end of the experiment had a live weight gain on 13,6% higher than in a control group. Calves which were fed with the additive were characterized by more stretched constitution, had well developed thorax and good development of skeleton in comparison with analogues from the control group.