<p><strong>Background.</strong> In sub-Saharan Africa, pasture is the most used practice in ruminant production, and grazing areas characteristics varied in different environment. To improve ruminants’ performances, the quality of forages represents one of the most important factors to keep under control. <strong>Objective.</strong> To quantify the effects of grazing stocking rate on the nutrient composition, energy content and <em>in vitro</em> fermentation characteristics including volatile fatty acids (VFA) and methane production (CH₄) of two local perennial grasses <em>Dactyloctenium aegyptium</em> L. and <em>Leptochloa caerulescens </em>L. <strong>Methodology.</strong> The forage samples were collected in three locations (Zinvié, Gakpé, Adounko) characterized by different stocking rate (low, medium and high). Their chemical composition, energy content and <em>in vitro</em> fermentation characteristics, including CH₄ production, were determined. <strong>Results.</strong> <em>D.</em> <em>aegyptium </em>showed the<em> </em>highest crude protein, energy content, organic matter degradability and VFA production (p&lt;0.01) when collected in Zinvié, whereas the highest (p&lt;0.01) structural carbohydrates (NDF) content was detected in Gakpé area and the highest CH₄ production was recorded from the sample collected in Adounko (p&lt;0.01). Contrariwise, <em>L. caerulescens</em> showed the highest level of crude protein and degradability (p&lt;0.01) when collected in Zinvié, whereas it proved the highest NDF content and the lowest lignin values (p&lt;0.01) when collected in Adounko. The highest CH₄ level was obtained from the sample collected in area of Gakpé (p&lt;0.01). Higher (p&lt;0.01) <em>in vitro</em> VFA production were recorded in samples collected in Adounko and Gakpé than in the Zinvié. <strong>Implications.</strong> The results obtained in this study highlight the significant influence of urbanization and herd concentration, as well as of other environmental conditions, on the nutritional value and potential environmental impact of the studied perennial grasses. <strong>Conclusion.</strong> Samples from high grazing stocking rate locations produced more <em>in vitro</em> methane. Further <em>in vivo</em> studies are needed to confirm these results.</p>