The experiment involved two groups, control and treatment, with probiotic supplementation to the latter. Haematological and serum biochemical parameters were assessed at 0 and 4 months of feeding trial. The probiotic, P. pentosaceus RM119, was administered at 10⁸ CFU/calf/day. Various haematological parameters, serum biochemical and erythrocytic antioxidant profile were investigated. Statistical analysis revealed no significant impact on haematological parameters. Serum biochemical profiles remained within normal ranges, indicating the overall well-being of experimental animals. Erythrocytic antioxidant glutathione showed an increase, suggesting a potential positive influence on antioxidant defenses. The study concludes that P. pentosaceus RM119 supplementation is safe and may offer health benefits in buffalo calves, warranting further exploration in animal health and welfare.