Sources of rumen enhancers including nitrate, chitosan extract and shrimp shell meal could modulate nutrient degradability and in vitro gas fermentation

Abstract

The objective of this research was to investigate the effects of nitrate, chitosan extract or shrimp shell meal on in vitro degradability and gas production kinetics. The study was arranged in a 2 × 7 factorial arrangement in a completely randomized design (CRD). Factor A was two ratios of roughage (R) to concentrate (C) ratio, R:C ratios at 60:40 and 40:60 (R:C), and the other factors were as several kinds and levels of additives (Non: non supplementation; Low-Ni: supplementation with 7 mg of KNO3; High-Ni: supplementation with 14 mg of KNO3; Low-CE: supplementation with 1.6 mg of chitosan extract (CE); High-CE: supplementation with 4.8 mg of chitosan extract; Low-SSM: supplementation with 8 mg of shrimp shell meal (SSM) and High-SSM: supplementation with 24 mg of SSM). Cumulative gas production was significantly decreased in the supplemented group. When increasing the level of a concentrate feed, propionate (C3) and total volatile fatty acid were enhanced, while acetate (C2) and C2 to C3 ratios were reduced (P < 0.05). The C3 and total VFA concentrations were increased with the supplementation of nitrate, chitosan extract and shrimp shell meal. CH4 production by nitrate, chitosan extract and shrimp shell meal addition was found to be lower than that of the control treatment.

Keywords

• Rumen enhancer
• methane
• feed resources
• manipulation
• degradability