Inoculation of exogenous lactic acid bacteria exerted a limited influence on the silage fermentation and bacterial community compositions of reed canary grass straw on the Qinghai-Tibetan Plateau.

AIMS

This study evaluated the effects of exogenous lactic acid bacteria (LAB) on silage fermentation and bacterial community of reed canary grass (RCG) straw.

METHODS AND RESULTS

The leaf, stem and whole crop of RCG straw were separately ensiled in small bag silos, without (control) or with inoculation of two exogenous LAB (LP, Lactobacillus plantarum; LB, Lactobacillus buchneri), and stored at ambient temperature of <20°C. Inoculation of exogenous LAB decreased (P < 0·05) bacterial alpha diversity and shifted (P < 0·05) bacterial community compositions, but did not change (P> 0·05) the relative abundance of Lactobacillus. Particularly, inoculation of LB increased (P < 0·05) acetic acid and propionic acid contents, decreased (P < 0·05) butyric acid (BA) and ammonia-N contents, separated (P < 0·05) the bacterial community in silage. However, the exogenous LAB inoculated silages were characterized by main distribution of yeasts, presence of undesirable bacterial genera such as Clostridium and high levels of BA and ammonia-N.

CONCLUSION

Inoculation of exogenous LAB exerted a limited influence on the silage fermentation and bacterial community compositions of RCG straw on the Qinghai-Tibetan Plateau.

SIGNIFICANCE AND IMPACT OF THE STUDY

Commercial LAB inoculants are not always efficient on enhancing silage quality and stability. Thus, an alternative additive for inhibiting undesirable microbes during storage is important to improve RCG silage quality on the Qinghai-Tibetan Plateau.