Pediococcus acidilactici strains as silage inoculants for improving the fermentation quality, nutritive value and in vitro ruminal digestibility in different forages.

AIMS: To examine the characteristics of three isolated Pediococcus acidilactici strains (LTG7, LOG9 and LH9) and evaluate their effects on silage quality, nutritive value and in vitro ruminal digestibility in a variety of forages.

METHODS AND RESULTS: One commercial inoculant Lactobacillus plantarum MTD-1 (G) and three isolated lactic acid bacteria (LAB) strains were measured by morphological, physiological and biochemical tests. All the LAB strains were added to Italian ryegrass (Lolium multiflorum Lam.), tall fescue (Festuca arundinacea Schred.) and oat (Avena sativa L.) for ensiling 30 days in laboratory silos (1 L), respectively. Isolated strains could grow normally at 5-20°C, pH 3.5-7.0 and NaCl (3.0%, 6.5%), and were identified as P. acidilactici by sequencing 16S rDNA. In Italian ryegrass and oat silages, all inoculants obviously (P<0.05) increased lactic acid (LA) contents, LAB numbers and in vitro dry matter digestibility (IVDMD), and decreased pH, undesirable microorganism numbers, butyric acid and ammonia nitrogen (NH3 -N) contents compared with the corresponding controls. LTG7, LOG9 and G silages in Italian ryegrass and oat had markedly (P<0.05) higher LA content and IVDMD, and lower pH and NH3 -N contents than LH9 silages. In tall fescue silage, LAB inoculants had no obvious (P>0.05) effect on fermentation quality, while markedly (P<0.05) enhanced IVDMD.

CONCLUSIONS: Based on our results, strains LTG7 and LOG9 had similar potential with the commercial inoculant G in silage making.

SIGNIFICANCE AND IMPACT OF THE STUDY: Few studies involved inoculation of silage with P. acidilactici in different forage types. Analysis of effects of LAB strains with their physiological and biochemical characteristics help understand how LAB inoculants affect the digestibility. This article is protected by copyright. All rights reserved.