Enteric methane is one of the main sources of Green House Gaz produced by ruminant livestock. Traditional pastoral systems use local natural grassland resources for livestock feeding, including a wide diversity of ligneous forages browsed by ruminants in West Africa. However few studies assessed the methane emissions of such forages. This study analyzed a large collection of ligneous and herbaceous forages, looking for estimating their methanogenic potential by using their biochemical composition predicted by NIRS and two models available in the literature (Sauvant et al. 2011, Jayanegara et al. 2012). Results showed a higher CH4 production in ligneous forages and tropical grasses when compared to tempered grasses (+10.3 vs+7.0 % respectively). However, ligneous forages contain some tannins at higher concentrations, which according to the models would tend to decrease the methanogenic potential (-16.8% and -2.3%), thus nuancing the first methane emissions results.