Effect of banana flower powder on rumen fermentation, synthesis of microbial protein and nutrient digestibility in swamp buffaloes

Abstract

Replacement of chemical compounds by dietary sources as rumen enhancers have been of great interest and concern by researchers. Four, rumen-fistulated swamp buffalo bulls with average liveweight of 365 ± 15.0 kg were randomly assigned to treatments, to investigate the impact of banana flower powder (BAFLOP) as a rumen modifier on pH, rumen fermentation, nutrient digestibility, microbial protein synthesis and volatile fatty acids. All buffaloes were allotted according to a 4 × 4 Latin square design. Dietary supplementation treatments were as follows: 2 g concentrate/kg bodyweight (BW; T1), 15 g concentrate/kg BW (T2), 15 g concentrate/kg BW plus BAFLOP 300 g/head.day (T3) and 15 g concentrate/kg BW plus BAFLOP 600 g/head.day (T4). Untreated rice straw was fed ad libitum. The findings showed that total feed intake was increased in buffaloes fed a diet supplemented with concentrate at 2 g/kg BW, while rice straw intake was reduced. Nutrient digestibility was increased by BAFLOP supplementation at both levels (T3 and T4; P < 0.05). Ruminal pH dropped (5.9) in buffaloes fed with concentrate at 15 g/kg BW, while buffaloes with BAFLOP supplementation could maintain ruminal pH when fed with high-concentrate diet. Ruminal ammonia-nitrogen increased in the buffaloes fed concentrate at 15 g/kg BW, especially with BAFLOP supplementation. Feeding high-concentrate diet increased the concentrations of ruminal total volatile fatty acids and propionic acid (C3), while the concentration of acetic acid and the acetic acid:C3 ratio and methane production were subsequently reduced (P < 0.05). In addition, efficiency of microbial protein synthesis was increased by the BAFLOP feeding (P < 0.05). In the present study, using BAFLOP as a dietary rumen enhancer at 300–600 g/head.day resulted in an increased rumen pH, C3 concentration, nutrient digestibility and microbial protein synthesis, while mitigating ruminal methane production. Higher nutrient digestibility and lower ruminal methane production, more dietary energy and production efficiency are expected.