Optimizing mangrove-derived tannin extract for sustainable ruminant feeding: A strategy to balance nutrient digestibility and methane mitigation

This study evaluated the effects of supplementation with mangrove fruit extract (Sonneratia alba) as a tannin source on rumen fermentation dynamics, nutrient digestibility, and methane reduction. Four ration treatments were tested with different tannin contents from mangrove leaf extracts (0%, 0.5%, 1% and 2%). The results revealed a significant reduction in the protozoan population and methane emission, from 25.68 ± 1.05 ml/g OMD (control) to 19.34 ± 0.98 ml/g OMD (2% tannin). However, higher tannin concentrations decreased the digestibility of dry matter, organic matter, and microbial biomass. The 1% dose resulted in the best balance between fermentation efficiency, methane reduction, and minimal impact on other fermentation parameters. This study supports the use of S. alba tannins as a sustainable feed additive to improve rumen efficiency while reducing environmental impact.