METABOLIC ACTIVITY OF LACTIC ACID BACTERIAL STRAINS AFTER THEIR INTRODUCTION INTO ALFALFA HAYLAGE

Abstract

Objective. Study the metabolic activity of strains of lactic acid bacterial strains after their introduction into alfalfa haylage as a component of preservatives. Methods. Microbiological (determining the number of microorganisms, obtaining antibiotic-resistant mutants of bacterial strains), zootechnical (pH level, accumulation and ratio of organic acids in the fermentation process), statistical. Results. Lactobacillus plantarum KT-L18/1str, L. plantarum 32str strains introduced into the haylage substrate are stored in the feed in an active state for a long time and at day 30 of fermentation take a dominant position among native lactic acid bacteria, retaining 80 % of the acid-forming capacity and antagonistic activity against Staphylococcus aureus. The best results of the action of the studied lactic acid bacteria (LAB) after introduction into alfalfa haylage were obtained when the mass was dry-cured to a moisture content of 60–61 %, while the share of lactic acid in the total amount of organic acids formed in the experimental variants of the haylage ranged from 85.5 % to 89.3 % versus the control, where the share of lactic acid reached only 42 %. Increasing the degree of feed acidification in experimental variants at a given alfalfa moisture content ensured a decrease in the butyric acid content to 1.12–1.7 % versus 26.3 % in the control variant. Treatment of alfalfa haylage dry-cured to a moisture content of 38–39 % with strains of lactic acid bacteria did not affect the increase in the proportion of lactic acid. Conclusion. The use of probiotic L. plantarum KT-L18/1str and L. plantarum 32str made it possible to establish their competitiveness and metabolic activity in the process of alfalfa haylage preparation. The use of LAB probiotic strains for alfalfa haylage preparation improved fermentation processes, in particular, when dry matter content was at the level of 39–40 %.