Effects of Dietary Fiber and Benzoic Acid on Growth Performance, Nutrient Digestibility, Reduction of Harmful Gases, and Lipid Profiles in Growing Pigs

We assessed the possibly synergistic effects of dietary fiber (DF) and benzoic acid (BA) in growingfinishing pigs. In total, 96 growing pigs ([Landrace × Yorkshire] × Duroc) with an average initial body weight (BW) of 22.82 (±0.24) kg were selected and provided the dietary supplements based on their BW in a 2 × 2 factorial experiment, with the respective factors being fiber (low vs. high; 140 g/kg, 160 g/kg NSP, respectively) and BA (0, 5 g/kg benzoic acid) in six replicate pens consisting of four pigs per pen. Sugar beet pulp was used as a DF source, at 50 g/kg of the diet. All diets were formulated to contain 14.44 ME MJ/kg and 190 g/kg CP. This experiment was conducted to evaluate the growth performance, nutrient digestibility, and reduction of harmful gases and serum metabolites. There was no significant difference in feed intake and weight gains during treatments. Fiber levels and benzoic acid addition did not affect the dry matter, nitrogen and gross energy digestibility. Also, no interaction was found between fiber level and benzoic acid treatment. There was no difference in NH₃, but RSH and H₂S gases emissions show significant reduction with fiber and benzoic acid treatment. Serum metabolites, including lipoprotein and cholesterol, were also apparently unaffected by these treatments. Thus, the addition of 50 g sugar beet pulp per kg of growing feed as a DF source and the addition of BA had no significant impact on the growth performance of pigs during the growth period.