This study evaluated the effects of partially substituting Berseem clover (BC) with Moringa Oleifera leaves on lactating Barki ewes' performance. Three cannulated rams (51.50±4.0 kg, body weight) were used to evaluate the ruminal degradation of DM, NDF, and ADF for Moringa Oleifera leaves (ML) using the in situ nylon bag method. The true dry matter digestibility, total gas production (ml/400 mg DM), and fiber fractions degradability were investigated using in vitro batch culture. A lactation trial was conducted using fourteen multiparous lactating Barki ewes (averaging 43.5±0.4 kg, body weight) randomly assigned into two equal groups (seven each). The control group's basal diet consists of a concentrated feed mixture and Berseem clover (50:50). The treatment group was fed ML as a replacement for BC at a level of 15% (150 g/kg DM). Results showed no significant effect of ML on in vitro nutrient digestibility and milk production and composition. However, the treatment group showed numerically higher values for all nutrients' digestibility and produced more milk with a higher fat content. In addition, the plasma albumin and glucose concentrations both were increased significantly while the triglyceride level was reduced slightly (p<0.05) after ML substitution. In conclusion, moringa leaves could be utilized as a replacement for Berseem clover at a level of 150 g/kg DM without any adverse effect on the performance of lactating Barki ewes.