The effects of stage of maturity and lactic acid bacteria inoculants on the ensiling characteristics, aerobic stability and in vitro digestibility of whole‐crop oat silages

Abstract

AbstractThis study evaluated the effect of three isolated lactic acid bacteria (LAB) inoculants on the ensiling characteristics, aerobic stability and in vitro digestibility of low dry matter whole‐crop oat silages (WCOS). The oats were harvested at two stages of maturity, boot and filling stages, and then inoculated with 1 × 106 cfu/g fresh material of Lactobacillus plantarum (LP), Lactobacillus rhamnosus (LR) and Lactobacillus buchneri (LB). After 45 days of ensiling, the three LAB inoculants increased lactic acid (LA) concentrations (p < .05) and decreased ammonia nitrogen (NH3‐N) content (p < .05) for both of the two stages of WCOS; the LP‐ and LR‐treated silages exhibited lower pH values and higher Flieg's points than the control and LB‐treated silages (p < .05); LB‐treated silages resulted in higher acetic acid contents than in the other treated silages (p < .05). After exposure to air for 7 days, the control and LB treatments had higher aerobic stability than the LP and LR treatments (p < .05). The Flieg's points and aerobic stability at the filling stage were greater than that at the boot stage. With no LAB inoculants, the in vitro dry matter digestibility (IVDMD) at the boot stage was higher than that at the filling stage. At the filling stage, LB‐ and LR‐treated silages had higher IVDMD than the control and LP‐treated silages (p < .05). It was concluded that the fermentation quality and aerobic stability of oats harvested at the filling stage was higher than that at the boot stage. LP and LR inoculants improved the fermentation quality but reduced the aerobic stability of WCOS. The IVDMD of WCOS at the filling stage was improved by adding LB and LR inoculants.