Effects of Phenyllactic Acid, Lactic Acid Bacteria, and Their Mixture on Fermentation Characteristics and Microbial Community Composition of Timothy Silage

Abstract

This study investigated the effects of phenyllactic acid (PL), lactic acid bacteria (LAB), and their mixture on fermentation characteristics and microbial community composition of timothy silage. Timothy silages were treated without (CK) or with PL [10 mg/kg fresh matter (FM) basis], LAB inoculant (IN; a mixture of <i>Lactobacillus plantarum</i> and <i>L.buchneri</i>, 10⁵ cfu/g FM), and their mixture (PI) and stored at ambient temperature (5°C∼15°C) in a dark room for 60 days. Compared with CK, all treated silages showed lower (<i>P</i> < 0.05) levels of butyric acid and ammonia-N. Treatment with PL enhanced (<i>P</i> < 0.05) the crude protein preservation of silage by favoring the growth of <i>L. curvatus</i> and <i>Saccharomyces cerevisiae</i> and inhibition of lactic acid-assimilating yeast belonging to <i>Issatchenkia</i> during ensiling. In particular, treatment with PL advanced (<i>P</i> < 0.05) the productions of lactic acid and volatile fatty acid in IN-treated silage. Therefore, PL used as a new additive exhibited potential for improving silage fermentation when it is combined with LAB IN during ensiling.