This experiment was conducted to study the effect of chemical and biological treatments of pruning peach trees by-products (PTBP) on chemical composition, degradability, cell wall constituents, digestibility and nutritive value and its feeding effect on productive performance of growing sheep. Thirty Ossimi lambs with average body weight 18.00±0.20 kg and 4 months old were used in this study for 120 days. Lambs were distributed into five similar groups (6 lambs each) and randomly assigned to five experimental rations. The five respective rations composed of concentrate feed mixture (CFM) + roughage (PTBP), the control ration (R1) contained untreated PTBP; (R2) treatedPTBPwithTrichoderma reesei; (R3)treated PTBP with Trichoderma viride;(R4) treated PTBP with Trichoderma reesei + Trichoderma viride and (R5) 3% urea treated PTBP. The DM, OM and CP disappearance and effective degradability (ED) va lues were in situ determined. The digestibility and nutritive values of experimental rations were determined using fifteen adult Ossimi rams. Rumen liquor and blood samples were collected at the end of collection period. The results showed that fractions of DM (a&b) and (ED) were significantly (P<0.05) increased with treated PTBP either with urea or fungi compared to control (untreated PTBP). The highest degradable values of DM, OM and CP were observed with R4. Nutrient digestibility and feeding values (TDN and DCP) were higher (P<0.05) for rations containing treated PTBP than control. The highest values of TDN and DCP were observed for R4. Digestibility of cell wall constituents (NDF, ADF, cellulose and hemicellulose) were improved by treatments. Concentrations of rumen parameters (NH₃-N and TVFA's) were significantly increased by treatments. However, no significant differences were found in blood constituents (total protein, albumin, globulin, GOT, GPT and urea) among the different experimental groups. Blood constituents were generally normal in all experimental groups. Growth performance with respect to total body weight gain and average daily gain (ADG) were improved by biological treatments. The same trend was observed for feed conversion and economic efficiency and the best values were recoded with R4. It was concluded that inclusion of treated PTBP to rations of growing Ossimi lambs could improve their performance especially treatment of PTBP with fungi.