Effects of liquid and fermented liquid feeding on energy, dry matter, protein and phosphorus digestibility by growing pigs

Two experiments were conducted to compare the apparent ileal digestibility (AID) of dry matter (DM), gross energy (GE) and crude protein (CP) and the apparent total tract digestibility (ATTD) of DM, GE, and P by growing pigs fed a diet in dry form to values obtained with pigs fed the same diet in a liquid form or in a fermented liquid form. A diet consisting of maize (728. g/kg), soybean meal (240. g/kg), soybean oil (10 g/kg) and vitamins and minerals was formulated and used in both experiments. In Exp. 1, the diet was fed to pigs as a dry diet or as liquid diets that were produced immediately before feeding by mixing the dry diet and water in a 1:1 ratio or in a 1:3 ratio. In Exp. 2, the diet was fed to pigs as a dry diet or as one of two fermented liquid diets. The fermented liquid diets were produced by mixing the dry diet with water (1:3 ratio) 24. h before feeding. Either 10 (F10) or 50% (F50) of the fermented feed was left in the fermentation tanks when new feed and water were added. Results of Exp. 1 showed that there was a tendency (P<0.10) for a reduction in the AID of DM, GE and CP when dry feed and water were mixed in a 1:3 ratio, but this was not the case when dry feed and water were mixed in a 1:1 ratio. The ATTD of DM, GE, and P was, however, not affected by the addition of water to the dry feed regardless of the dry feed to water ratio. In Exp. 2, pigs fed both fermented diets had lower (P<0.05) AID of CP than pigs fed the dry diet, but the AID of DM and GE were not affected by fermentation. The ATTD of DM in pigs fed the F50 diet tended (P=0.06) to be greater than in pigs fed the dry diet or the F10 diet, but the ATTD of GE and P were not affected by fermentation.