Biological Activity of Lactic Acid Based Feed Additive and its Physiological Effect on the Animal Organism

The data obtained as a result of the study of the enzymatic activity of the lactic acid based feed additive LAFA, based on various bacteria, are consistent with the results of the research presented in the publications on the matter, concerning the fact that probiotic bacteria have enzymatic activity. The conducted studies revealed the leading enzymatic properties of bifidobacteria in the composition of LAFA, in comparison with other investigated microorganisms. Various strains of bifidobacteria constitute, according to some sources, up to 90% of the representatives of the normal flora of poultry intestine. Bifidobacteria are found in all parts of the intestine. All the detected enzyme groups synthesized by them, thus, participate in all enzymatic processes in the processing of feed in the gastrointestinal tract. The results of the study on determining the concentration of human interferon-alpha-2 in the intestine of laboratory mice when fed with LAFA, based on bifidobacteria, lactobacilli, propionic acid bacteria and lactic thermophilic streptococcus, showed the stimulating effect of the additive on the production of interferon in the intestine of the mice. The greatest stimulating effect on the production of interferon was obtained from the LAFA based on Lactobacilli (LAFA-L) and bifidobacteria (LAFA-B). It is these types of microorganisms (lactobacilli and bifidobacteria) that are dominant, irreplaceable and useful in the intestines of animals and poultry. The studies on determining the antibiotic susceptibility of opportunistic pathogenic strains in the presence of LAFA showed a general tendency of increase in the antibiotic susceptibility of the studied strains of microorganisms after cultivation with LAFA based on monocultures of probiotic microorganisms, with a simultaneous decrease in the number of cultures with low susceptibility and an increase in the number of the susceptible ones with an increase in the period of their cultivation. However, the determination of the degree of antibiotic susceptibility (change in the zone of growth retardation of microorganisms) of a conditionally pathogenic microflora revealed the absence of such a pattern.