This work examined the influences of partial replacement of clover hay with 15 or 30% of untreated pruning peach trees by-products (UPPT) or those biologically treated (BTPPT) with effective microorganisms (EM1) on growing rabbit performance. Seventy-five NZW weaned rabbits (6-weeks-old; average body weight 657 g) were assigned randomly into five groups. Five pelleted diets were used, control and other four diets (15 or 30% UPPT or BTPPT were replaced of clover hay). The biological treatments improved the chemical composition of pruning peach trees by-product, in terms of increasing crude protein and decreasing crude fiber as compared to UPPT. Final body weight, body weight gain, feed conversion ratio and performance index values were enhanced when rabbits fed either 15 or 30% BTPPT. Digestibilities of crude protein, crude fiber, nitrogen free extract, total digestible nutrients and digestible energy were increased with rabbits fed diets containing BTPPT. Carcass traits studied, moisture, crude protein (CP), ash, ether extract (EE) of rabbits meat, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, total cholesterol, creatinine and urea were not different between the applied treatments. Net revenue and economic efficiency were increased with the biological treatment. Conclusively, BTPPT could be used up to 30% with positive effects on growth performance, physiological functions and economic efficiency in NZW growing rabbits.