Probiotics colonize the intestines and exert an antibacterial effect on pathogens. Therefore, probiotics could be used as a preventive agent against lethal infections. To isolate probiotic microorganisms, 116 bacterial strains were isolated from healthy cow's milk and were subjected to Gram-stain, morphology and biochemical analyses, Vitek analysis, and 16S rRNA analysis. One of the strains identified as Bacillus (B.) thuringiensis 87 was found to grow very well at pH 4.0~7.0 and to be resistant to high concentrations of bile salts (0.3~0.9% w/v). B. thuringiensis was susceptible to the antibiotics used in the treatment of bovine mastitis, yet it exhibited an antimicrobial effect against Staphylococcus (S.) aureus 305. Moreover, it protected mice from experimental lethal infections of E. coli O55, Salmonella typhimurium 01D, and S. aureus 305 through a significant induction of interferon-γ, even at four-week post-administration of B. thuringiensis. Although oral administration of B. thuringiensis 87 did not provide significant protection against these lethal challenges, these results suggest that B. thuringiensis 87 could be a feasible candidate as a probiotic strain.

Lactic acid bacteria have been reported their beneficial roles on host including reduction of infectious diarrhea problems. In this study, preventive effect of Lactobacillus (L.) reuteri HY25101 and L. johnsonii HY25103 on porcine epidemic diarrhea virus (PEDV) was investigated in suckling piglets. Two groups of one day old PEDV naive piglets were orally administered L. reuteri HY25101 and L. johnsonii HY25103 for three days respectively before challenge with lethal dose of PEDV. In second experiment, passive immunized one day old piglets using colostrums containing PEDV specific IgA were used. The survival rates of the L. reuteri HY25101 administered group were significantly higher than that of L. johnsonii HY25103 administered group and viral shedding was rapidly diminished in L. reuteri HY25101 administered group. Interestingly piglets born from the sow immunized with attenuated PEDV vaccine were not completely protected from PEDV challenge, however coadministeration of L. reuteri HY25101 and colostrums containing PEDV specific IgA were more effectively prevent PEDV infection. These results suggested that dietary treatment using L. reuteri HY25101 could reduce diarrheal problem and mortality rate caused by PEDV in suckling pigs. In addition, L. reuteri HY25101 could be used as one of effective compensation treatment with attenuated live vaccine for PED.

The growth characteristics and the properties of the Enterococcus faecium (E. faecium) isolated from intestine of slaughting pig were examined in order to confirm whether it will be used practically as probiotics or not. E. faecium was identified by morphological and biochemical tests including of final confirming by API strep kit. Among 264 samples, 44 isolates (16.7%) of E. faecium were observed as an exellent growth as a range of 1×10∨7 CFU/ml~3.3×10∨9 CFU/ml in viable bacterial count on MRI medium.

Jeotgal (salted seafood) has been one of major fermented foods in Korea for long time. Although there are many studies about Jeotgal in various aspects of food, its immunological importance on hosts has not been elucidated yet. In this study, we investigated if several bacteria isolated from Jeotgal may modulate the function of dendritic cells (DCs), powerful antigen-presenting cells equipped with special immunological capabilities. 4 Jeotgal bacteria were selected as representatives and used for experiments. To treat viable DCs, those bacteria were killed at 60¡� for 30 min. The viability of DCs treated with Jeotgal bacteria was verified and two isolates significantly induced high production of interleukin-12, a representative cell-mediated cytokine of DCs. Surface activation and maturation markers (MHC class II, CD40, CD86) of DCs were analyzed by flow cytometer. In addition, the treated DCs showed significantly high lymphocyte stimulatory capability compared to control DCs based on allogeneic mixed lymphocyte reactions. These observations suggest that Jeotgal isolates can function as immunostimulating bacteria in hosts, like Lactobacillus. Taken together, these experimental evidences may broaden the use of Jeotgal isolates in immunological fields in addition to as a fermented food.

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 a probiotic lactic casein feed additive DKM which was developed in the Institute of Microbiology of the National Academy of Sciences of Belarus. The analyzed additive contained specially selected lactic-acid bacteria with a high bioartificial potential of metabolites. In course of the experiment there was studied the consumption of fodders (milk; oats; mixed fodders) by experimental calves; dynamics of live weight gain in the beginning and at the end of the experiment; average daily weight gain. Also, there were analyzed the background indexes of blood serum of calves, as well as the indexes of blood serum of calves in a month after application of DKM additive. Research results showed that application of the feed additive DKM promoted better palatability and use of fodders and rendered positive influence on animal productivity. Also, there was marked the normalization of metabolism that was proved y the laboratory tests of blood serum.

Investigation of influence of probiotic Dialact and immunostimulant Alveozan on digesting of nutritive substances by broiler chickens of Kobb-500 cross, as well as control over their individual development were realized in the conditions of the Republic of Belarus. The first (control) group of chicken was given standard well-balanced ration. Chickens of the second group were administrated immunostimulant Alveozan in dose of 10 mkg/kg of live weight with drinking water once a day in course of 5 days, with 10 days interval till the end of the growing period. Chickens of the third group were administrated preparation Dialact in dose of 0,1-0,2 ml with drinking water once a day in course of 3 days, with 14 days interval till the end of growing period. Chickens of the fourth group were given Alveozan in dose of 10 microgram/kg of live weight once a day in course of 5 days with 10 days interval, and Dialact in dose 0,1-0,2 ml once a day in course of 3 days, with 6 and 14 days interval. Research results showed that complex application of probiotic Dialact and immunostimulant Alveozan increased the viability of chickens on 100%, average live weight - on 5,1%, average daily weight gain - on 5,1%. Administration of Dialact and Alveozan, both separately and in complex, increased the digestibility of nutritive substances of mixed fodders: application of nitrogen increased on 1,93-6,38%, application of calcium decreased on 10,41-12,54%, phosphorus use increased on 2,38%

Research of the influence of biologically active preparations of natural origin on zoological indices and quality of animal products was studied by the example of their application in broiler chicken diets in the conditions of the Republic of Belarus. On the basis of realized research it was established, that application of biologically active substances immunoamplifier Alveozan, probiotic Dialakt, probiotic Bifidoflorin liquid, prebiotic Biofon and prebiotic Biofon AIL (produced in the Republic of Belarus) did not render negative effect on quality of animal products (all studied meat samples had high quality). The received results testify to necessity of complex application of the above-stated preparations. Application of biologically active preparations made it possible to increase livability of growing birds on 100%, average live weight increase from 1,9 up to 5,1%, daily average weight gain - from 1,9 up to 5,1%, improvement of feed conversion ratio - from 18,3 up to 21%. All studied biologically active preparations made it possible to restore the physiological environment in poultry intestines, normal flora, to suppress the growth of pathogenic microorganisms. The above mentioned preparations could be applied both with preventive, and with the medical purposes

Analysis of efficiency of prebiotics and probiotics and different systems of their application for the focused formation of bacteriocenosis of gastro-intestinal tract of calves was realized in the conditions of the Republic of Belarus. There were used 7 groups of calves: 1 – clinically healthy; 2 – calves with diarrheal syndrome which did not get preparations; 3 – calves were administrated daily with liquid probiotic Bifidoflorin Zhidkij in dose 20 ml in course of 20 days; 4 – calves were administrated daily with prebiotic Biofon with colostral milk or milk in dose 20ml in course of 20 days; 5 – calves were administrated daily with prebiotic Biofon-AIL in dose 20 ml in course 20 days; 6 – calves were administrated with probiotic Bifidoflorin Zhidkij simultaneously with prebiotic Biofon; 7 – calves were administrated with probiotic Bifidoflorin Zhidkij in combination with prebiotic Biofon-AIL. In course of studies there was analyzed the age-specific dynamics of bifidus bacteria, lactic acid bacillus, and Escherichia quantities in calves excrements. Research results showed that application of the proposed prebiotics and probiotics promoted the earlier and active contamination of intestines with obligate anaerobe gram-positive flora with its dominative position in relation to gram-negative nonsporeforming facultative anaerobic flora. At the stage of the second aging immunodeficiency the analyzed preparations rendered the resolving effect. The highest positive indexes were obtained after combined application of probiotic Bifidoflorin Zhidkij with prebiotic Biofon-AIL

Evaluation of antagonistic activity of strains of lactic and bifid bacteria, metabolite producers, as well as the treatment and prophylactic efficacy of Laktimet and Batsinil probiotics was realized in the conditions of the Republic of Belarus. In course of study there were estimated 29 strains of lactic acid bacillus of different kinds, 13 strains of bifid bacteria and 35 strains of bacillus (Bac. subtilis and Bac. pumilis). There were studied 3 strains of bifid bacteria: Bifidobacterium adolescentis MS-42; Bifidobacterium adolescentis BIM V-01; Bifidobacterium adolescentis BIM V-87; 2 strains of lactic acid bacillus: Lactococcus lactis subsp. Lactis BIM V-132, Lactococcus casei subsp. rhamnosus BIM V-189; and 6 strains of Bacillus subtilis. Research results showed that the main part of the studied strains had steady antagonistic activity to test-cultures of opportunistic pathogenic bacteria. Zone of growth delay of test-cultures of the main quantity of strains (from 54 up to 92%) was from 11 up to 30. Research results showed that application of cell-free probiotics Laktimet and Batsinil promoted the increasing of resistance by means of increasing or lowering of total protein, insignificant increasing of blood serum bactericidal activity and increasing of phagocytic activity of leukocytes on 7,3%