Evaluation of Essential Oils as Additives during Fermentation of Feed Products: A Meta-Analysis

Abstract

Essential oils (EOs) are secondary metabolites of plants with antimicrobial functions that can be used as silage additives, but their effectiveness has been inconsistent. Therefore, this study aimed to evaluate the effects of EOs as silage additives on nutritional quality, fermentative products, microbial population, and in vitro rumen fermentation. A total of 17 articles consisting of 113 studies (comparisons) were selected for meta-analysis. The results showed that EO supplementation increased several parameters of nutrient contents such as dry matter (DM), crude protein (CP), and ether extract (EE) (p p p p < 0.05). These results showed that EO supplementation improved several nutrient qualities such as DM, CP, and EE, inhibiting mold growth and stabilizing rumen pH.

Keywords

• essential oil
• fermentability
• feed additive
• meta-analysis
• silage