The problem of treatment of acute digestive disorders with signs of diarrhea in calves remains relevant and important, as there are no sufficiently effective drugs, including antimicrobial effects. The low effectiveness of antibiotics and other chemotherapeutic agents and therapies in the vast majority of farms dictates the need to find new drugs. The purpose of our work was to study the significance of opportunistic microorganisms in the etiology of calving diarrhea. The research was conducted at farms of Lviv and Volyn regions. The incidence of newborn calves with acute digestive disorders with signs of diarrhea ranged from 36.8 to 100%, and mortality ranged from 17.4 to 30.8%. Bacteriological study was subjected to patmaterial from 20 dead calves at the age of 1–7 days. In this case, 88 cultures have been isolated from the internal organs, mesenteric lymph nodes, bone marrow, brain, walls and intestines. According to the culture – morphological properties, the cultures were classified into the following species: Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, Diplococcus capsulatus, Clostridium perfringens. In the bacteriological study of all microorganisms isolated - Diplococcus capsulatus 29.5%, Escherichia coli 30.7%, Pseudomonas aeruginosa 19.3%, Clostridium perfringens 11.4%, Proteus vulgaris 9.1%. Out of the 14 households, the causes of the disease of calves with acute gastrointestinal disorders in 35.7% of cases were certain opportunistic pathogens (Escherichia coli, Diplococcus capsulatus, Pseudomonas aeruginosa, Clostridium perfringens, Proteus vulgaris). In most farms (64.28%), the disease was caused by association (2, 3 and more) types of microbes. The pathogenic properties of the isolated cultures were tested on white mice. In determining the pathogenicity of isolated cultures from dead calves on white mice, the most pathogenic were microorganisms of the species Pseudomonas aeruginosa. Experimental mice (42.0%) died within 6–12 hours after infection. Highly pathogenic were mixed cultures of E. coli, diplococci, Pseudomonas aeruginosa, which killed 58.0% of infected mice 24–48 hours after infection. This indicates an increase in the pathogenic properties of microorganisms in the association. In order not to allow the passage of conditionally pathogenic microflora, it is necessary to adhere to the sanitary regime in dispensaries and maternity departments, and the terms of disinfection with variable sectional retention.

Pasteurleozy is a factor disease. The manifestation of pathogenic action of pasteurals occurs under conditions of influence on a susceptible organism of a number of negative factors, which are conventionally divided into contributing and adversarial. In the etiology of pasteurial infection, they play a decisive role. The problem of the struggle against rabbit pasterelosis in our country is paid insufficient attention. The analysis of the documents of the state veterinary report gives grounds to assert that the tension of the epizootic situation with regard to rabies pasteurse in the country remains unexplored. So, in official data on outbreaks of rabies pasterelosis during the last 10 years there are separate reports, from which it is impossible to make a comprehensive assessment of the epizootic process of this infection in Ukraine. There is no data on the characteristics of circulating serotypes of Pasteurella multocida in rabbit farms. There are only brief information about the spread of the disease in the rabbits in certain regions, in particular, the Luhansk, Donetsk and Zaporizhzhya oblasts. These reports indicate a poor condition for the maintenance of rabbits and an insufficient level of antiepizootic measures, which, according to the authors, is the main reason for the spread of pasteurellosis. Given these data, it can be assumed that pasteurellosis is a rather common disease of rabbits, not only in the east of Ukraine, but also in the whole country. In the system of antiepirosis measures of rabies pasteurellosis, the leading role is given to active immunization of the susceptible animal population. The article presents the results of the analysis of the domestic and world market of veterinary immunobiological means for the specific prevention of this infection. It is shown that only one vaccine against pasterelosis of rabbits of foreign production and no domestic vaccine has been registered in Ukraine. A comparative analysis of the main components of foreign vaccines and vaccines developed by our scientists was carried out. The most common inactivator in pasteurial vaccines is formaldehyde, despite the fact that it destroys the capsule, which plays an important role in the formation of the immune response and immunity tension. All foreign vaccines as a preservative contain thiomersal – an organic derivative of mercury. As an adjuvant mineral oil and aluminum hydroxide are used, both substances are reactogenic for the rabbit organism. It has been shown that the immunogenic component of pasteurial vaccines includes several serotypes of P. multocida.

The purpose of the research was to clarify the effect of chicken broilers feeding in the composition of mixed fodder with Vitamins E and C on the cellular link of non-specific resistance of the organism and, in particular, the parameters of pseudoiesinophils phagocytosis in blood. The research was carried out on chickens broiler -308 grown in the farm "Fedyuk M" in the Zolochiv district of Lviv region. The keeping of the chickens was cellular with free access to feed and water. Experiments were conducted in 4 groups of broiler chickens of 100 chicks in each according to the scheme: the control group was fed with the standard feed (SC) according to the existing norms recommended for the cross ROSS-308; the first experimental group in addition to the SC received vitamin Е 1g/10 kg of mixed fodder; the second experimental group received vitamin C 2.5 g/10 kg of mixed fodder; the third experimental groups in addition to the ration received Vitamin C 2.5 g/10 kg and Vitamin E 1 g/10 of mixed fodder. For carrying out of immunological researches in chickens blood was taken in different age periods: 27-, 34-and 41-day-old age. In the whole blood, the phagocytic activity of pseudoiesinophils (FA), phagocytic index (FI) and phagocytic number (FF) were determined. For research, the daily culture of Escherichia coli (strain VKM-125) was used. The stimulatory effect of vitamins E and C in the composition of mixed fodder for chicken broiler broilers on the indices of pseudoiesinophils phagocytosis of blood was determined. As evidenced by a significantly higher phagocytic activity, phagocytic index and phagocytic count of pseudoiselinophils in blood of chickens in the experimental groups by comparison with the control group. At the same time there was a direct correlation between phagocytic activity and phagocytic index and index in blood of chickens broiler in experimental groups. At the same time, the ability of blood pseudoiesinophils to phagocytosis of microbial cells was higher in chicken broilers, which were fed with vitamin E and C.

Chickens in the control group received a standard ration, the first experimental – ration with the addition of tocopherol acetate, the second experimental – ascorbic acid, and the third – a complex of these vitamins. On the basis of the conducted researches the influence of vitamin supplements on the indexes of oxidation intensity of lipid and protein structures was analyzed. The intensity of the processes of oxidative modification of proteins largely depends on the level of vitamins E and C in the ration of broiler chickens. Supplementation with vitamin C and with vitamin E resulted in an inhibitory influence on the content of OMP products, the level of which is largely regulated by the enzyme and non-enzymatic links of the antioxidant protection system. Searches have shown the stimulating influence of the addition of vitamins on the activity of antioxidant enzymes. In particular, SOD activity increased by 19 % on the 34th day, by 32 % on the 41st day, whereas glutathione peroxidase activity was 5.7 and 20.8 %, respectively, compared to the control chickens group. An increase in the activity of antioxidant enzymes occurred against the background of a decrease in the intensity of oxidation processes. At the same time, there was also an increase in the content of recovered glutathione in the blood of chickens of the second and third experimental groups at 34th and 41st days of age. Thereby, searches have shown that supplementing the ration with vitamins E and C with a positive influence on the organism's adaptive capacity and antioxidant potential, which is extremely important to ensure the metabolic homeostasis of chickens during critical periods of their cultivation.

Scientists of both human and veterinary medicine combine their potential to develop new or improve old instruments in order to rein the problem of foodborne salmonellosis in Ukraine. According to the experience of European poultry industry, the most effective measure for the prevention of avian salmonellosis is total vaccination against salmonellosis of laying hens and breeding birds. In our country, the epizootic situation of salmonellosis of animals and poultry is consistently favorable. At the same moment nearly 90% of foods born Salmonella outbreaks are of poultry and egg products origin. In other words the source of major source of Salmonella agent is avian origin. Currently no vaccines of native origin have been registered in Ukraine. Although there have been numerous attempts to develop a vaccine against avian salmonellosis. The purpose of our work is to evaluate the antigenicity and immunogenicity of the two experimental series of bivalent inactivated emulsified vaccine against avian salmonellosis in production conditions. During the examination of the vaccine in the poultry farm it was found that for 21 days after the re-introduction of the vaccine, the titers of antibodies to the mono-antigens S. Typhimurium, Enteritidis and Gallinarum in the Agglutination Test (AT) and Indirect Hemagglutination Test (IH) were: 1 : 640–1280 to 1 : 2560–5120 respectively. This indicates high antigenicity of the vaccine. No significant difference between the levels of antibodies to Typhimurium and Enteritidis antigens was detected neither in AT nor IH. At the same time the levels of antibodies to mono-antigen Gallinarum were markedly lower in both reactions (1 : 160–1 : 320 – in AT and 1 : 320–1 : 1280 – in IH), but high enough to indicate that the vaccine creates a tense cross-humoral immunity to Salmonella surface antigens of Gallinarum serovar. The results of study of immunogenicity of the vaccine show that the vaccine is highly immunogenic. It means that after control infection of vaccinated hens none of tested Salmonella strains (S. Typhimurium and S. Enteritidis) were isolated from any organs, whereas in the control non-vaccinated group of birds both Salmonella test-strains were isolated from all organs. The obtained results provide a basis for further phases of the vaccine estimating followed by its registration in the prescribed manner.