T he following study was designed to evaluate demineralized calf foetal growth plate (DCFGP) effects T he following study was designed to evaluate demineralized calf foetal growth plate (DCFGP) effects on bone healing process. A critical size defect (10 mm) was created in the radial diaphysis of 20 rabbits and on bone healing process. A critical size defect (10 mm) was created in the radial diaphysis of 20 rabbits and then supplied with DCFGP (treatment group, n = 10) or the defect was left empty (control group, n = 10). then supplied with DCFGP (treatment group, n = 10) or the defect was left empty (control group, n = 10). Radiographs of each forelimb were taken postoperatively on the 1 Radiographs of each forelimb were taken postoperatively on the 1 st st day and at the 2 day and at the 2 nd nd , 4 , 4 th th , 6 , 6 th th and 8 and 8 th th weeks post weeks post injury to evaluate bone formation, union and remodeling of the defect. The operated radiuses were removed injury to evaluate bone formation, union and remodeling of the defect. The operated radiuses were removed on the 56 on the 56 th th postoperative day and were evaluated for histopathological criteria. This study demonstrated that postoperative day and were evaluated for histopathological criteria. This study demonstrated that DCFGP, as a xenogenic biomaterial, could promote bone regeneration in critical size defects with a high DCFGP, as a xenogenic biomaterial, could promote bone regeneration in critical size defects with a high regenerative capacity, and could be an attractive alternative for reconstruction of the major diaphyseal defects regenerative capacity, and could be an attractive alternative for reconstruction of the major diaphyseal defects of the long bones in animal models. of the long bones in animal models.