Digestibility of Energy and Crude Protein in Korean Rice Wine Residues Fed to Pigs

Two experiments were conducted to determine the digestibility of energy and Crude Protein (CP) in Korean Rice Wine Residues (RWR) using in vitro and in vivo approaches. In the in vitro experiment, 2-step and 3-step in vitro disappearance procedures were employed to determine in vitro Ileal Disappearance (IVID) and in vitro Total Tract Disappearance (IVTTD) of nutrients, respectively, in corn, a Soybean Meal-Wheat Mixture (SBMW), RWR and the experimental diets used in the in vivo experiment. In the in vivo experiment, 3 Jeju Island native pigs fitted with a T-cannula in the distal ileum with an initial mean body weight of 74.8±5.4 kg were individually housed in pens equipped with a feeder and a nipple drinker. A replicated 3×3 Latin square design was employed with 3 dietary treatments, 6 periods and 3 animals. Three experimental diets based on the corn and SBMW with a constant ratio (corn:SBMW = 3.06:1) were formulated to contain 0, 15 or 30% of RWR. All diets contained 0.5% chromic oxide as an indigestible index. Korean RWR had greater IVID of Dry Matter (DM) than corn and SBMW (p<0.05). The IVID of CP in RWR was less than that of corn and SBMW (p<0.05). The IVTTD of DM in RWR was greater than that of corn but less than that of SBMW (p<0.05). The IVID of CP linearly decreased as the inclusion rate of RWR increased (p<0.001). The digestible energy concentration (kcal/kg DM) in diets increased linearly with an increase in RWR in the diets (p = 0.001). The apparent and standardized ileal digestibility of CP in the diets showed a linear decrease (p<0.001) as the inclusion rate of RWR increased. In conclusion, Korean rice wine residues have a high digestible energy concentration and may be used in swine diets with attention to protein utilization.