Antagonistic properties and peculiarities of inter-strain interactions of probiotic microorganisms were investigated. The study of the antagonistic activity of probiotic strains was carried out by the methods of perpendicular strokes (or delayed antagonism) and the diffusion method (block modification) in relation to opportunistic and pathogenic microorganisms. Most probiotic strains had moderate to high antagonistic activity against both gram-positive and gram-negative pathogens. The results obtained allowed us to select the most active strains, namely L. plantarum AS-41, L. acidophilus A-14, B. subtilis S-2 and B. subtilis S-18, which have a high probiotic potential. To assess biocompatibility, the method of co-cultivation of the selected strains on a modified agar MRS medium was used. The strains that showed biocompatibility of the type “mutual neutrality” or “contact progression” were selected to create a consortium of probiotic microorganisms. Further study of the investigated strains of probiotic bacteria opens up the possibilities of their use for the manufacture of a combined preparation for veterinary purposes, for the prevention and treatment of diseases of the gastrointestinal tract of farm animals.

The composition of the intestinal microflora of rats with experimental antibiotic-associated dysbiosis and after its correction with a biological product based on lactic acid and propionic acid microorganisms was studied. The results obtained indicate the normalization of the number of microorganisms when using the suspension form of the drug and make it possible to recommend its use in clinical practice for the correction of intestinal microflora disorders in animals.

This article presents the results of a study of the parameters of acute toxicity and sensitizing properties of a microbiological additive based on probiotic strains L. acidophilus IV138 and B. subtilis GA24 on White Wistar rats and White Giant rabbits. The acute toxicity class of the prototype feed additive was established in accordance with the fundamental document OECD Test № 423 “Acute Oral Toxicity - Acute Toxic Class Method” (2001). The evaluation of the irritating properties of the microbiological preparation was carried out by the method of skin applications and using the test conjunctival test. The research results showed that the probiotic preparation does not have acute toxicity when administered orally to warm-blooded animals, sensitizing properties in the conjunctival test and skin application. According to the results of experimental studies, the feed additive containing L. acidophilus IV138 and B. subtilis GA24 strains is classified as a low-hazard product.

The data of the veterinary and sanitary examination of the meat of Indo-dwellers after the use of the anthelmintic compound «K-55» in their diet were obtained. The conducted studies of the veterinary and sanitary examination of poultry carcasses, all samples were of good quality and met the requirements of GOST 31470-2012, GOST R 54354-2011 and «Rules for veterinary examina-tion of slaughtered animals and veterinary and sanitary examination of meat and meat products».