Natural Strategies for Improving the Antioxidant Status and Health of Rabbits: The Role of Biochar and Tribulus terrestris

This study evaluated the effect of dietary supplementation with biochar and Tribulus terrestris (TT) on oxidative stress and metabolic parameters in New Zealand White rabbits. A total of 80 weaned rabbits (35 days of age) were assigned to four groups (20 each): a control group (C) and three experimental groups supplemented with 0.25% biochar (E1), 0.25% biochar and 0.1% Tribulus terrestris (E2), or 0.1% Tribulus terrestris (E3). The feeding experiment lasted 78 days following a 7-day adaptation period. Hematological, biochemical, and redox parameters, including malondialdehyde (MDA), glutathione (GSH), total reducing capacity (FRAP), immunoglobulin G (IgG), and testosterone levels, were assessed and analyzed using one-way analysis of variance (ANOVA). Rabbits from group E1 exhibited the highest FRAP values (8.16 µmol/L; p < 0.05), whereas MDA concentrations were significantly elevated in groups E1 and C (2.02 and 1.83 µmol/L; p < 0.05), indicating increased lipid peroxidation. Groups E2 and E3 showed lower MDA levels (1.38 and 1.59 µmol/L; p < 0.05) and higher IgG concentrations (44.72 and 37.82 ng/mL; p < 0.05) compared to the control, suggesting improved antioxidant defense and immune status. GSH levels were significantly higher in groups E1 and E2 (6.34 and 6.79 µmol/L; p < 0.05). No adverse changes were observed in basic hematological and biochemical parameters. The results indicate that dietary supplementation with biochar and T. terrestris is safe and can beneficially modulate redox balance and immune response in rabbits, confirming their potential as natural feed additives in sustainable rabbit production.