The present study was conducted to evaluate silage quality, concentration of pesticides residues, degradability and feeding value of silage containing cotton stalks (CS) and 1‘t cut of berseem (B) treated with or without inoculants of lactic acid bacteria, (LAB) and supplemented with or without dried yeast (DY). The silages were: 1- (CS + B) silage; 2- (CS + B) silage plus BY; 3- (CS + B) silage treated with LAB and 4- (CS + B) silage treated with LAB plus DY. Silage treated with LAB leads to good quality silage. Concentration of pesticides residue in all silages were less than the limits of quantification (0.05 mg! kg). Diet containing silage treated with LAB and supplemented with DY had higher (P: 0.05) nutrients digestibility coefficients, feeding values, nitrogen utilization, effective degradability (96) of DM and OM. So, silage treated with LAB and supplemented with DY could be recommended for ruminants feeding during summer season.