Essential oil blends of Copaifera langsdorffii and Eucalyptus staigeriana Branch on fermentation parameters, microbial counts, and aerobic stability of whole-plant corn silage

ABSTRACT The primary concern in corn silage is aerobic deterioration. This study aimed to evaluate the impact of essential oil (EO) blends extracted from copaiba (Copaifera langsdorffii) (Co) and Eucalyptus staigeriana Branch (ES) on the fermentation parameters and losses, nutritional value, microbial counts, and aerobic stability of corn silage. A completely randomized design was employed with four treatments and four replicates. The following treatments were employed: control (CON) – corn ensiled without EO; blend 50:50 (50 % ES plus 50 % Co); blend 75:25 (75 % ES plus 25 % Co); blend 25:75 (25 % ES plus 75 % Co). The dose was administered at a rate of 500 mg kg–1 of ensiled mass (as-fed basis). The chemical composition, in vitro degradability, NH3-N, pH, acetic, propionic, and butyric acids, aerobic stability, and microbial counts of silages were evaluated. The 75:25 blend reduced (p < 0.038) crude protein (CP) by 7.96 % compared to the 25:75 blend. However, the 50:50 blend reduced (p < 0.03) the hemicellulose (HEM) content of the silage in comparison to the other treatments. The blends were observed to increase (p = 0.046) the concentration of acetic acid. The propionic acid concentration was reduced by 88.13 % with the 25:75 blend compared to the 50:50 blend. The blends increased (p = 0.003) gas losses. The fungal population was drastically reduced (p = 0.048) by the 25:75 blend compared to the other treatments. It can be concluded that the 50:50 blend resulted in high concentrations of acetic and propionic acids, thereby improving the aerobic stability of corn silage.