Effects of Lactobacillus plantarum and hydrolytic enzymes on fermentation and ruminal degradability of orange pulp silage

Abstract

The current study was carried out to examine the effect of inoculants, enzymes and mixtures of them on the fermentation, degradability and nutrient value of orange pulp silage. Orange pulp was treated with water (control), inoculant (Lactobacillus plantarum), enzymes (multiple enzyme) or inoculants + enzymes prior to ensiling (denoted C, I, E and I+E). For ensiled orange pulp, 84 kg of orange pulp were mixed with 16 kg of wheat straw as an absorbent. Three mini-silos were prepared for each treatment and ensiled for 90 days. Data of each silo within each silage treatment was averaged and used as an experimental unit in a completely random design. Silage pH, total fatty acid and ammonia nitrogen were determined. Silage pH and lactic acid concentration were lowest and highest respectively for I and I+E (p<0.01), while the lowest (p <0.01) NH3N concentration (49.8 g/kg total N) was observed in I compared to the control. The lowest acetic and butyric acid concentrations were observed in I and I+E compared with the control (p <0.01). The highest metabolizable energy (ME), net energy lactation (NEl), digestible organic matter in dry matter (DOMD), short chain fatty acid (SCFA) and microbial protein (MP) values were observed for I+E (p <0.01). The in vitro degradability of dry matter (IVDMD) was highest (P<0.01) in I+E, while the highest (P<0.01) effective degradability of DM (EDDM) was observed for E and I+E treatments. These results indicated that the bacterial inoculants and combination of enzyme and bacterial inoculants clearly improved silage fermentation characteristic. In addition, the ME, DOM, MP and IVDMD of I+E were significantly improved.

Keywords

• orange pulp silage
• degradability
• enzymes
• Lactobacillus plantarum