APPARENT DIGESTIBILITY OF SELECTED PROTEIN INGREDIENTS FOR LARGER YELLOW CROAKER PSEUDOSCIAENA CROCEA

Apparent digestibility coefficients of dry matter, crude protein, crude lipid, energy and phosphorous in white fish 3 期李会涛等:大黄鱼对几种饲料蛋白原料消化率的研究 375 meal, brown fish meal, meat and bone meal, soybean meal, peanut meal, rapeseed meal and cottonseed meal were determined respectively for large yellow croaker.Apparent digestibility coefficients were determined by using a reference diet with 011% chromic oxide indicator and test diets that contained 70% reference diet, by weight, and 30% of the test feed ingredient being evaluated.The fish averaging 1510 ±116g were reared in floating sea cages.Feces samples were manually stripped from anes2 thetized fish to prevent contacting with water.Apparent digestibility coefficients of dry matter ranging from 4316% to 7010%, and the values for rapeseed and cottonseed meal were lower (5016% and 4316%) than those for other tested feedstuffs.Appar2 ent digestibility coefficients of energy reflected the differences in dry matter digestibility, the higher digestibility coefficients were observed for white fish meal and brown fish meal of 8216% and 8015%, and lower digestibility coefficients were found in rape2 seed meal (6614%) and cottonseed meal (4219%).Apparent digestibility coefficients of crude protein ranged from 7019% to 9214% indicated that these feedstuffs could be efficiently utilized by large yellow croaker.Apparent digestibility coefficients of crude lipid were higher than 7412% except for cottonseed meal (6113%).Apparent digestibility coefficients of phosphorous were low (from 913% for cottonseed meal to 6213% for white fish meal) and showed significant differences among the feed in gredients.These data provide more precise informations concerning nutrient and energy utilization of large yellow croaker for these protein ingredients and will allow ingredient substitutions in practical feed based on the levels of fish nutrients.