Fermentation Quality, Chemical Compound, and In Vitro Digestibility of the Oil Palm Fronds and Mucuna bracteata Mixed Silage Treated by Various Inoculants

The present study was aimed to investigate the effects of starter bacteria types and differences in forage composition (oil palm fronds (OPF) and Mucuna bracteata (MB)) of OPF silage on physical quality, fermentation characteristic, nutrient content, and digestibility. The research was conducted based on 3x3 factorial design using 3 types of inoculants (EM4, Bacillus sp., and Lactobacillus sp.) and 3 different forage proportions (28.35% OPF + 50% MB; 39.17% OPF + 39.17% MB; and 50% OPF + 28.35% MB), with four replications. The silage was incubated for 21 days, then its quality was observed including organoleptic tests, pH, lactic acid, reducing sugar, proximate analysis, and in vitro digestibility test. This study shows that the types of inoculants and the composition of silage significantly differed on the physical qualities (texture, aroma, and mold) (P<0.01), fermentation characteristics (pH before and after silage processing, lactic acid, ammonia, and reducing sugar concentration) (P<0.01), nutrient content (ash content, EE, CF, NDF, ADF, and lignin) (P<0.01), and nutrient digestibility (IVDMD, IVOMD, and IVCFD after 48 hours) (P<0.01). Bacillus sp. with 28.35% oil palm fronds (OPF) and 50% Mucuna bracteata (MB) resulted in the best quality silage in terms of texture, lactic acid content, decreasing sugar concentration, crude fiber, and lignin. The combination of EM4 with 28.35% oil palm fronds (OPF) and 50% Mucuna bracteata (MB) yielded the maximum nutritional digestibility, as measured by the IVCFD value