POTENSI TANAMAN LEGUM TROPIS DALAM STRATEGI PAKAN BERKELANJUTAN DAN MITIGASI GAS RUMAH KACA: TINJAUAN LITERATUR: Potential of Tropical Legume Plants in Sustainable Feed Strategies and Greenhouse Gas Mitigation: A Literature Review

Abstract

The livestock sector, particularly ruminant production, is a major contributor to greenhouse gas emissions, primarily methane (CH₄), generated through enteric fermentation. An effective and context-specific mitigation strategy for tropical regions is the supplementation of low-carbon local forages that utilize high-protein tree legumes rich in natural bioactive compounds. This review highlights several promising species, including Leucaena leucocephala, Indigofera zollingeriana, Moringa oleifera, Calliandra calothyrsus, Gliricidia sepium, and Sesbania grandiflora (turi), as strategic feed resources for sustainable livestock systems. Empirical studies have demonstrated that supplementation with these legumes at inclusion levels of 20–40% of dietary dry matter can reduce enteric methane emissions by 10–30%, enhance protein utilization efficiency, and improve rumen fermentation profiles by increasing propionate proportions. The presence of condensed tannins and saponins plays a crucial role in suppressing ruminal protozoa and methanogenic archaea without compromising animal performance. Nevertheless, several constraints remain, including potential mimosine toxicity in Leucaena, high tannin content in Calliandra, and variability in nutrient digestibility influenced by plant maturity and post-harvest processing. Future research opportunities include comprehensive in vivo trials to determine optimal inclusion rates, genetic improvement of low-toxin legume cultivars, and the application of life cycle assessment (LCA) to quantify environmental benefits across the production chain. Integrating agronomic innovation, nutritional optimization, and supportive policy frameworks is essential for scaling these practices. Overall, low-carbon local forage supplementation represents a pivotal approach for achieving climate-resilient, productive, and environmentally sustainable tropical livestock systems.