NUTRITIVE-VALUE OF WET DISTILLERS SOLUBLES FOR PIGS

Digestibility and nitrogen (N) metabolism were studied to evaluate the nutritive value of wet barley distillers' solubles (DSB) from an inte grated starch-ethanol process for pigs. Eight castrated male pigs (liv e weight 72-103 kg) were used in a 8 x 3 cyclic change-over design, wh ere the diets were arranged factorially 2 x 2. The corresponding facto rs were the protein source (DSB or soya bean meal (SBM)) and the prote in level (131 or 162 g crude protein (CP)/kg dry matter (DM)). Faeces and urine were collected in total. The four diets comprised barley, ba rley starch, minerals and vitamins with either DSB or SBM as the main source of protein. The digestibility of CP (p<0.001) and organic matte r (p<0.01) was higher in SBM than in DSB-based diets, but the digestib ility of ash (p<0.01) and ether extract (p<0.001) was higher in DSB th an in SBM-based diets. The digestibility coefficients of the nutrients calculated by regression were generally higher in SBM than in DSB. Th e digestibility of CP was 0.865 in DSB and 0.902 in SBM. The pigs on S BM-based diets retained more (p<0.001) and excreted less N in urine (p <0.001) than the pigs on DSB-based diets. The nitrogen balance paramet ers were closely related to lysine supplies, which were higher in SBM- based diets.