饲料蛋白质和能量水平对红姑鱼生长和鱼体组成的影响

采用 3× 3因子试验确定不同蛋白质和脂肪水平实用饲料对红姑鱼生长和鱼体组成的影响。初始平均体重为 2 .73g的试验鱼放养在 2 7个 2 .5m× 1.5m× 1.3m的网箱中 ,每箱放养 6 0尾。用饲料蛋白质水平为38% ,42 %和 46 % ,脂肪水平为 5 % ,8%和 12 %的试验饲料饲养鱼 8周。结果表明特定生长率和饲料系数以高蛋白质组 (HP ,46 % )显著高于中蛋白组 (MP ,42 % )和低蛋白组 (LP ,38% ) (P <0 .0 5 ) ;饲料脂肪水平对鱼的生长和饲料系数没有显著影响 (P >0 .0 5 ) ;随饲料DP/DE降低 ,脏体比和肝体比增加 ;随饲料可消化能增加 ,全鱼和肝脏的脂肪含量增加 ,但对机体的蛋白含量、氨基酸构成和灰分含量没有多大的影响。从本试验可初步认为红姑鱼幼鱼最适饲料蛋白质水平为 46 % ,可消化蛋能比 (DP/DE)为 119mg·kcal-1。

Effect of dietary protein and lipid levels on growth and body composition of juvenile Sciaenops ocellatus

A 3 ×3 factorial feeding trial was made to determine the effect of dietary protein level and lipid level on growth and body composition of Sciaenops ocellatus. Juvenile fish whose initial mean weight was 2.73g were randomly distributed in 27 nets (2. 5m ×1. 5m ×1. 3m) and were fed with test diets containing gradual protein levels (38 %, 42 %, 46 %) and lipid levels (5%, 8%, 12 %) for 8 weeks. It is found that specific growth rates (SPR) and feed conversion ratio (FCR) were significantly higher in fish fed with high protein diets (HP, 46 %) thanthosefedwithmediumproteindiets (MP, 42 %) andlowproteindiets (LP, 38 %) ( P <0.05). No significant difference was found among groups fed with different lipid levels diet in the same protein level ( P > 0. 05) . Viscerosomatic and hepatosomatic index increased with reducing of the dietary DP/ DE. Lipid content of whole body and hepatocrease increased with increasing of the dietary digestable energy. However , protein and ash content and amino acid composition of whole body were not affected by dietary treatment. It is recommended that the optimal dietary protein level and the ratio of protein and digestible energy (DP/ DE) of juvenile Sciaenops ocellatus are 46 % and 119mg·kcal -1.