The effect of sodium butyrate on growth and intestinal microflora of weanling pigs

Proc. Soc. Nutr. Physiol. (2005) 14 The effect of sodium butyrate on growth and intestinal microflora of weanling pigs (Einfluss von Na-Butyrat auf Wachstum und intestinale Mikroflora von Absetzferkeln). G. Biagi*, E. Vezzali, A. Piva and F.X. Roth – Bologna/Freising-Weihenstephan The period of five to eight weeks after weaning is a critical stage in most pork production systems. In the recent past, these problems were counteracted with widespread use of antibiotic substances and auxinic agents that may select antibiotic-resistant genes in intestinal pathogens with the possibility of a cross spread to human pathogens. Adding organic acids to piglet diets has been reported to be helpful in overcoming problems of the post-weaning period (1). Butyric acid is known to be the main energy source of the hindgut mucosa and has shown positive effects on growth when fed to weaned pigs (2). Aim of this study was the evaluation of the effect of feeding sodium butyrate (SB) on piglet growth and intestinal microflora. Methods: Immediately after weaning, 48 piglets were divided into four groups (12 animals per group, housed in individual cages) for a six week trial. Treatments were a commercial diet with a) no addition (control diet) or with b) 0.1%, c) 0.2%, and d) 0.4% of SB. Feed and water were provided ad libitum. Animals were weighed every week and feed consumption was recorded. At the end of the trial, six animals per group were killed. Samples of jejunum and caecum content were cultured for viable bacteria and pH, ammonia and short-chain fatty acids (SCFA) were determined. Results: Feeding SB at 0.4% improved piglet growth (P < 0.10). Intestinal bacterial counts and pH did not show any differences; lactobacilli in jejunum and lactobacilli, coliforms and clostridia in caecum averaged 6.1, 8.5, 6.6, and 6.2 log cfu/ml, respectively. Feeding 0.4% SB resulted in higher caecal ammonia than control (23.0 vs 15.9 mmol/l; P < 0.10) while ammonia in jejunum was not influenced by treatment. Iso-butyric acid in the jejunum was reduced by SB (-47%; P < 0.10). Interestingly, caecal iso-butyric acid was reduced by SB at 0.1% (-24%; P < 0.10) but increased by SB at 0.4% (+40%; P < 0.05). The other SCFA in jejunum and caecum were not affected by SB. Table 1. Live weight, average daily gain (ADG), daily feed intake and feed conversion rate (FCR) of piglets in the six weeks after weaning. Values are means of 12 animals ± SD. Final live weight ADG Daily feed intake FCR (kg) (g/d) (g/d) Control 26.81 ± 3.86 480 ± 73 773 ± 105 1.62 ± 0.07 Sodium butyrate 0.1% 27.98 ± 4.96 508 ± 104 805 ± 141 1.60 ± 0.08 Sodium butyrate 0.2% 27.45 ± 3.37 493 ± 65 777 ± 97 1.58 ± 0.06 Sodium butyrate 0.4% 28.85 ± 2,64* 528 ± 53* 835 ± 97 1.58 ± 0.05 *Different from control by P < 0.10. Conclusion: The present results show an improvement of animal growth when SB is fed at 0.4%. At the same time, SB at 0.4% increased caecal ammonia and iso-butyric acid concentrations, the both being metabolites resulting from bacterial proteolysis, but this effect was not observed when SB was fed at lower doses. Feeding SB to weaned pigs seems to have a positive effect on animal growth but further studies will be needed to better understand how SB influences animal performances and health. 1) ROTH, FX and KIRCHGESSNER, M (1998): J. Anim. Feed Sci. 7 (Suppl. 1), 25-33. 2) PIVA, A, MORLACCHINI, M, CASADEI, G, GATTA, PP, BIAGI, G and PRANDINI, A (2002): Ital. J. Anim. Sci. 1, 35-41. _______________________ *Department of Physiology and Animal Production, Faculty of Veterinary Medicine, University of Bologna, Via Tolara di Sopra 50, I-40064 Ozzano Emilia