Effects of dietary fibre source and enzyme supplementation on faecal apparent digestibility, short chain fatty acid production and activity of bacterial enzymes in the gut of piglets

The effects of fibre source, either wheat bran (WB) or maize cobs (MC), and dietary exogenous enzymes (ES) on performance and digestive parameters of weaned piglets were studied in 24 Duroc × Landrace male piglets, weaned at 21 days of age. There were four treatments arranged factorially, with two sources of fibre (WB or MC) and two concentrations of ES (0 or 0.15 g/kg) that contained 800 U/kg of endo-1,4-β-cellulase, 1800 U/kg of endo-1,3(4)-β-d-glucanase and 2600 U/kg of endo-1,4-β-xylanase. The digestibility of the neutral detergent fibre was higher (P<0.001) in diets containing WB and the digestibility of the acid detergent fibre increased with ES. Small intestine digesta contents (g/kg live weight) at slaughter were higher (P<0.01) in pigs fed MC than in pigs fed WB. Fibre source did not affect the amounts (mmol/l) of short chain fatty acids (SCFA) in the small intestine. However, replacement of WB by MC increased acetic acid and decreased butyric acid concentrations (P<0.05) in the caecum. In addition, pigs fed diets with MC as the major fibre source had lower (P<0.05) concentration of butyric acid in the colon than pigs fed diets with WB. Enzyme supplementation affected molar proportions of SCFA formed in the small intestine and tended to increase acetic acid, propionic acid and total SCFA concentrations in the colon of piglets fed WB (P<0.10). The xylanolytic and cellulolytic activities in the caecum and colon were higher (P<0.05) for piglets fed WB than for piglets fed MC. In conclusion, ES increased the digestibility of acid detergent fibre and neutral detergent fibre and the replacement of WB by MC reduced neutral detergent fibre and acid detergent fibre digestibility, caecal butyric acid production and hindgut activity of bacterial enzymes.