Influence of dietary benzoic acid addition on nutrient digestibility and selected biochemical parameters in fattening rabbits

The effects of two inclusion levels of benzoic acid (5 and 20 g/kg diet; B5 and B20, respectively) vs. a control (C) and an antibiotic (tiamulin) supplemented (A; 150 mg/kg) diet on nutrient digestibility and selected biochemical parameters were investigated in 48 weaned ( n = 12 per treatment) rabbits (35 days old). Blood samples were obtained (at 45 and 85 days of age) to measure erythrocyte glutathione peroxidase (GSH-Px) activity, plasma alkaline phosphatase (ALP) activity and Ca and P levels. At 56 days of age total tract apparent digestibility (TTAD) was determined. At the end of the trial (85 days) rabbits were slaughtered for subsequent measurements. GSH-Px activity was also determined in liver homogenates post-mortem. Benzoic acid inclusion level decreased linearly (P