本研究之目的為探討玉米酒粕對吳郭魚稚魚(Oreochromis niloticus O. aureus)成長及體組成之影響。基礎飼料中蛋白質的添加量為吳郭魚蛋白質需求量之30%,添加蛋白質的方式為魚粉及黃豆粉以1:2比例混合作為蛋白質來源的基礎,再以玉米酒粕取代黃豆粉蛋白質含量0%﹐8%﹐16%﹐24%, 32%及40%,總共六組,每組三重複,分別餵予初重10.22 ± 0.01g 之吳郭魚稚魚,於密閉式循環過濾系統中飼育六週。研究結果顯示:吳郭魚稚魚餵食玉米酒粕取代不同黃豆粉蛋白質含量的飼料六週後,魚體增重率以餵食玉米酒粕取代黃豆粉蛋白質含量16%組顯著(P<0.05)高於餵食0%、8%及40%組,其餘各組之間並無顯著差異;飼料效率、蛋白質效率及蛋白質獲得量與魚體增重率有相同的趨勢。魚隻肝體比以餵食玉米酒粕取代黃豆粉蛋白質含量8%顯著高於0%及40%組。魚體血液組成中之平均紅血球大小以餵食玉米酒粕取代黃豆粉蛋白質含量8%組顯著高於16%及32%組,其餘各血液指標並無顯著差異。此外,飼料中添加玉米酒粕對魚體組成並無顯著影響。結論:以魚體增重率與飼料中玉米酒粕取代不同黃豆粉蛋白質藉由拐點法(broken-line model) 迴歸分析,達到魚體最佳成長的玉米酒粕取代黃豆粉蛋白質含量為21.6%。 A growth trial was conducted to investigate effects of corn distiller’s dried grain with soluble (DDGS) concentration on growth and body composition of juvenile tilapia (Oreochromis niloticus O. aureus). Tilapia were fed 30% crude protein diets in which dietary protein was supplied by fish meal and soybean meal (ratios of fish meal protein to soybean meal protein were 1:2), and to have DDGS replacing soybean meal at 0%, 8%, 16%, 24%, 32% and 40% of soybean meal protein, respectively. Each diet was fed to triplicate group of tilapia (mean initial weight: 10.22 ± 0.01 g ) in a recirculating rearing system for 6 weeks. Fish fed diet with DDGS replacing 16% soybean meal protein had significantly (P<0.05) greater weight gain (WG) than fish fed diets with 0%, 8% and 40%. Feed efficiency (FE), protein efficiency ratio (PER), and protein gain of the fish had similar trend as the WG. Hepatosomatic index (HSI) was higher in fish fed diet with 8% than fish fed diets with 0% and 40%. Mean cropuscular volume (MCV) was higher in fish fed diet with 8% than fish fed diets with 16% and 32%, the other blood parameters was not different among the dietary groups. In addition no significant differences in whole body proximate composition. Conclusion: Weight gain analyzed by broken-line regression indicated that the optimum DDGS replacing soybean protein level for tilapia was 21.6%.