Effects of fermented and extruded wheat bran on total tract apparent digestibility of nutrients, minerals and energy in growing pigs

A pig digestibility trial was conducted to investigate the effects of fermentation or extrusion of wheat bran included in a basal diet on coefficients of total tract apparent digestibility (CTTAD) regarding dry matter (DM), organic matter (OM), crude protein (CP), crude fiber (CF), ether extract (EE), starch, energy (GE), phosphorus (P) and calcium (Ca). In the experiment, 9 growing pigs were allocated to a 3 × 3 Latin square design to measure the CTTAD of the basal diet containing different modified wheat bran variants, and therefore to demonstrate relative differences in the CTTAD among the diets as a result of wheat bran modification. The wheat bran was used in native form (NWB), as fermented bran ensiled with Lactobacillus paracasei and Lactobacillus plantarum (FWB) and as extruded wheat bran (EWB). Wheat bran variants were included at 200 g kg−1 in a phosphorus deficient basal diet. The obtained results show that the CTTAD of DM was increased when feeding the diet with FWB (+2%, P<0.05) instead of NWB (0.87). Likewise the CTTAD of OM was also increased with FWB (+2%, P<0.05), compared to NWB (0.88). Also the CTTAD of CF was improved with FWB and EWB (+9%, P<0.05), related to NWB (0.58). The CTTAD of ash was improved with FWB (+14%, P<0.05) compared to NWB (0.60). Correspondingly, the CTTAD values of P and Ca were also elevated when feeding the FWB diet. P-digestibility was increased in the FWB feeding group compared to those groups fed with NWB (+35%, P<0.05) and EWB (+53%, P<0.05). Regarding the Ca digestibility, similar results were obtained (P<0.05). While the CTTAD of energy was increased in the FWB (+3%, P<0.05) and EWB (+2%, P<0.05) feeding groups compared to that of NWB (0.85), the N-balance and the CTTAD of starch were not affected by the treatments. Nevertheless, the CTTAD of EE was enhanced in the FWB treatment group (+40%, P<0.05), and was also improved by extrusion (+30%, P<0.05) compared to the NWB (0.50) treatment. In conclusion, fermented and extruded wheat bran exert some significant influence on the apparent total tact digestibility of several essential nutrients, minerals and energy when included in a basal diet, whereby fermentation seems to be the more potent strategy, as positive effects on the CTTAD of P and Ca could only be observed in the feeding group with FWB.