Investigation of acute sub-acute toxicity of preparative forms (herbal infusion, tincture liquid extract and pulvis) of marsh cinquefoil (Comarum palustre) by the example of laboratory animals was realized in the conditions of the Republic of Belarus. White mice of both sexes with body weight of 18-20 g and white rats with body weight of 180-200 g were used in the experiment. Experimental preparations were administrated on empty stomach after 12 hours of absolute diet. The animals were supervised in course of 14 days. All changes in behavior were registered. Calculations of parameters of acute and average toxicity of all analyzed forms were presented. Research results showed that all analyzed preparative forms could be referred to the substances hazard category 4 (low-hazardous substances) with lethal dose 50 more than 5000 mg/kg of live weight. It was determined that the analyzed preparative forms proved to be highly effective against strongylatosis (Strongylata) of gastro-intestinal tract of sheep and calves

Results of studies of acute and chronic toxicity of control samples of long acting boluses on the basis of fenbendazole for the treatment of strongylatosis (Strongylata) of gastro-intestinal tract of cattle realized in the conditions of the Republic of Belarus were presented. White rats and mice were used for studying of acute and chronic toxicity of the prolonged anthelmintic. The preparation was tested in doses of 400; 800; 1200; 1600; and 2000 mg/kg of body weight. Prolonged anthelmintic was administrated introgastrally in the form of suspension. Preparation was reduced to fragments before application. White rats with body weight of 80-100 g were divided in three groups and were used for testing. Bolus of prolonged activity was reduced to fragments and mixed with feed before application. Rats ate the preparation during 30 day in dozes of 250 mg/kg, 375 mg/kg, and 500 mg/kg. Study of acute toxicity of preparation established that LD0 for white mice was 400 mg/kg; LD16 - 620 mg/kg; LD50 - 1080 (1062,7 / 1097, 3) mg/kg; LD84 - 1660, LD100 - 200 mg/kg. Signs of animal toxicosis were revealed in shakiness, depression, whiteness of visually accessible mucous coat, cramps. Catarrhal-haemorrhagic gastroenteritis and numerous effusions of blood on mucous coat of digestive tract were established at postmortem examination. There were no morphological changes in tissues of lungs, heart, liver and nephros. Eating of prolonged anthelmintic with feed during 30 days did not render toxicological influence on rats. There were no signs of intoxication, physiological deviations and no animal death. Research results showed that the analyzed prolonged anthelmintic could be referred the substance hazard category 3

While studying biochemical values that characterize rumen digestibility based on research agricultural experiment some results were obtained. These results prove that studied diets with increase of energy and raw protein concentration levels in dry matter influence positively at nitrous substances concentration activate micro flora motions and promote bio-synthetic processes in rumen fluid of experimental animals

There are the results of the scientific and economic experiment by the study of multifermentable supplement eniciencyin calves nutrition, it has been established that young animals with the supplementary ration by the and of the experiment have maintained the live weight on 11.4% higher compared with the control group of animals. The rate of natural phylactic power of an organism in young animals with the supplementary ration was considerably higher

Investigation of influence of complex probiotic preparation Laktimet obtained by means of cultivation of bifidus bacteria and lactic acid bacillus on morphological indexes of pancreatic gland of laying hens was realized in the conditions of the Republic of Belarus. Two groups of laying hens of 121-130 days old were used in the experiment. The experimental hens were given probiotic Laktimet with water in dose of 1 ml/head every day in 4 cycles during 7 days and with 7 days intervals. Total condition, dynamics of body weight, and egg production were estimated. Research results showed that body weight of experimental hens increased on 6,4 % on the 10-th day; on 12,1% - on the 24-th day; on 6% - on the 40-th day; and 7,5% - on the 50-th day of experiment. Pancreas weight of experimental hens increased on 4-9%. Acinus size increased on 11%. Morphological indexes in exocrine pancreatic cells showed that altitude of basal pole increased on 3-7%. Application of probiotic Laktimet rendered positive influence on laying hens that was evident in increasing of their productivity (there was an increasing of live weight on 4-8%, and egg-laying capacity – on 18-33%). The positive dynamics of the majority of morphofunctional indexes of exocrinous and endocrine parts of pancreatic gland proved its significant role in maintenance of general state of laying hens and metabolic processes

Determination of regular variations of macromorphological and topographical characteristics of thymus gland, spleen, thyroid gland, and atrabiliary capsules of swamp beavers (Myocastor coypus) at the postnatal ontogenesis was realized in the conditions of the Republic of Belarus. Taking into consideration active participation of immune and endocrine system organs in metabolic processes and vicarious and adaptive reactions there were revealed species and age-specific anatomical peculiar features of thymus gland, spleen, thyroid gland, and atrabiliary capsules of swamp beavers that made it possible to broader knowledge in the sphere of species, age-specific, breed and topographic anatomy

It is determined that diets with protein digestibility of 61-66% in organism of a calve activate fermentative processes in rumen, increase digestibility of nutrients at 3,8-10,1% that allows to obtain the average weigh gains of 1036-1075 g, that is at 4,2-8,1% higher than that of control group at forage spends of 6,79-7,04 forage units