Evaluation of sweet orange essential oil on fermentation and aerobic stability of corn silage

Abstract

ABSTRACT Corn silage is susceptible to losses through aerobic spoilage. Therefore, this study aimed to evaluate increasing sweet orange essential oil levels in chemical composition, in vitro degradability, losses, fermentation parameters, microbial count, and the aerobic stability of corn silage. The experiment was carried out in a completely randomized design with four treatment levels: Control (CON), ensiling corn without sweet orange essential oil; 200 mg kg–1,400 mg kg–1, and 600 mg kg–1 of ensiling mass with four replicates per treatment. Sweet orange essential oil affected both the dry matter (p = 0.035) and the organic matter (p = 0.021), presenting quadratic behavior. Sweet orange essential oil did not affect (p ≥ 0.05) in vitro dry matter degradability, in vitro neutral detergent fiber degradability, or gross energy. Sweet orange essential oil had a quadratic effect (p = 0.022) on the acetic acid concentration in corn silage. There was a tendency (p = 0.097) for sweet orange essential oil to reduce the ammoniacal nitrogen linearly. The levels of sweet orange essential oil did not influence losses by gases or effluents (p ≥ 0.05). We observed no effect of sweet orange essential oil on Lactic acid-producing bacteria populations or fungi (p ≥ 0.05). Furthermore, increasing sweet orange essential oil levels decreased temperature (p = 0.02) over time but did not influence pH (p = 0.404). Sweet orange essential oil does not affect in vitro degradability, fermentation parameters, nor microbial count in corn silage. However, the 600 mg of ensiling mass increases corn silage’s acetic acid concentration and aerobic stability.

Keywords

• antifungal
• conservation
• fermentative quality
• secondary plant metabolites