Studies of morphological and morphometrical particularities of rennet of newborn calves with different degree of antenatal hypotrophy were realized in the conditions of the Republic of Belarus. Scientific-and-production researches were spent in 2007 - 2008 on the basis of agricultural production co-operative Dembrovo (Shchuchinskij district, Grodno area, Belarus), agricultural production co-operative Okhovo (Pinsk district, Brest region, Belarus) and research laboratory of Grodno State Agrarian University (Belarus). For an estimation of morphofunctional maturities there were used 165 1-day old calves. Research results showed that in the studied calves the basic indexes of glanderous apparatus of rennet proved the different degree of morphofunctional immaturity. In calves with hypertrophy in the first days after birth there stated an active morphogenesis of all cytological components of rennet

Development of a new national preparation for the preventive maintenance of cow mastitis, fissures of milking tubes skin of cow udder was realized in the conditions of the Republic of Belarus. The preparation Maz' Solnechnaya ("Unguent Solnechnaya") did not contain antibiotics, hormones and other synthetic components. Natural components of a preparation provide long anti-inflammatory action, stimulate local blood circulation, regeneration of epidermis and accelerate processes of healing of microtraumas. Besides it possesses high efficiency at preventive maintenance of mastitises at cows.

Data оn evaluations of therapeutic efficacy of albendazol and fenbendazol agaonst acute and chronic forms of larval cestodiasis of animals were studied in the conditions of the Republic of Belarus by an example of experimentally infested sheep and rabbits. Application of albendazol and fenbendazol both separately and in complex with antioxidant vitamin and mineral additive against the chronic forms of cysticercosis tenuicollis and cysticercosis pisiform was inefficient. But application of albendazol against acute form of cysticercoses caused the lowering of invasion intensity in shepp and rabbits in 3 times, fenbendazol – in 2,6 times. Application of anthelmintic agents in complex with vitamin and mineral composition promoted the lowering of invasion intensity (in 5 and 4,1 times, respectively) and prevented the disease development in 60% of animals.

Study of parasitocoenoses of digestive system of Ayrshire breeds of cows and heifers was realized in the conditions of the Republic of Belarus. In course of investigation there was presented a highly efficient universal sedimentation and flotation method with centrifuging for diagnostic of low intensity infestations of cattle. Heifers of Ayrshire breed the total infestation with parasites of gastro-intestinal tract was 100%. Species composition of parasites per one animal was 2,0 +/- 0,258. In winter period the components of parasitoses of a digestive tract were the following: eimeria, strongylats, fascioles, moniezia, nematodes, trematodes and cestodes. In cows of Ayrshire breed the total infestation was also 100%, mixed infestation – 70,0 %. Species composition of parasites per one animal was 2,55 +/- 0,170. In winter period the components of parasitoses of a digestive tract were the following: eimeria, strongylats, fascioles, and capillariasis

After the pathomorphological and histological studies of innards of fallen experimental animals in all realized experiments it was found that sheep and lambs infected with pneumoviral infections (Parainfluenza-3, Adenoviridae, respiratory streptococcosis infection) with their additional infestation with radioactive substances there was stated the acceleration of infectious process, and disease recrudesced up to 2-5 and more times (depending on irradiation doze). The immunity of sheep and lambs decreased caused by reproduction of viruses, and in acute cases animals died but in cases of mild forms the disease transformed into chronic form and caused animal death.

Determination of chronic toxicity of a new selenium-containing preparation Aesel was realized in the conditions of the Republic of Belarus. There was realized endermatic administration of the experimental preparation to laboratory white mice. Studying of sensitivity of some organs and systems of mice and revelation of a degree of reversibility of processes caused by active substances of the drug was realized. The main clinical, pathomorphologic, biochemical, hematological changes in the organism of laboratory animals with induced chronic toxicity were determined.

Evaluation of influence of monoinvasions and mixed parasitoses on quality and quantity composition of microbiocenosis of gastro-intestinal tract of carnivore was realized in the conditions of the Republic of Belarus. Changes in intestinal microflora of gastro-intestinal tract of dogs with monoinvasions and associated parasitic diseases in comparison with indexes of healthy animals were typical for disbacteriosis and took place towards the reduction of quantity of normal intestinal microflora (bifidobacteria and lactobacteria) and increasing of transient microorganisms: aerobic bacilli, micromicetes, proteus spp, staphylococci, streptococci.