Abstract An experiment was conducted to delineate the effect of varying level of dietary protein with balanced level of limiting amino acids such as lysine and methionine on growth, feed utilization, body indices and digestive enzymology of snubnose pompano, Trachinotus blochii reared in low saline water. There were four experimental diets formulated with 350 (CP350), 400 (CP400), 450 (CP450) and 500 g/kg (CP500) crude protein and each with 100 g/kg crude fat and were assigned to four treatments, CP350, CP400, CP450 and CP500 respectively. Totally eighty four fingerlings with the body weight in the range of 16−18 g were randomly distributed in four treatment groups with each of three replicates. Fish were fed to apparent satiation twice daily with the assigned experimental diet. At the end of 13 weeks of feeding trial, weight gain percentage (WG%) and specific growth rate (SGR) of fish fed with CP400 and CP450 diets were significantly higher than those of fish fed with CP350 and CP500 diets. Growth rate on metabolic body weight (GRMBW), daily growth coefficient (DGC) and average daily growth (ADG) were higher in CP400 group and lower in CP350 group. The viscerosomatic index (VSI), hepatosomatic index (HSI), gastrosomatic index (GSI) and intra-peritoneal fat ratio (IPFR) showed an increasing trend as the crude protein content of the experimental diet increases and the maximum value was witnessed in CP500 treatment. Crude lipid and protein content of whole body tissue was found highest in CP400 and lowest level was noticed in CP350 group. The maximum intestinal protease activity was noticed in CP400 group. In conclusion, analysis of second degree polynomial regression revealed that the optimum dietary protein level could be in the range of 395.3–426.7 g/kg for maximum growth of juvenile snubnose pompano.

中文翻译：

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日粮蛋白质分级水平与限制性氨基酸等量水平对在低盐水中饲养的鲭鱼 (Lacepede, 1801) 生长、饲料利用、身体指数和营养成分的影响

摘要 一项试验研究了不同水平的日粮蛋白质和平衡水平的限制性氨基酸（如赖氨酸和蛋氨酸）对低盐水饲养的鲇鱼生长、饲料利用、身体指标和消化酶学的影响。有四种实验日粮用 350 (CP350)、400 (CP400)、450 (CP450) 和 500 g/kg (CP500) 粗蛋白配制，每种日粮均含有 100 g/kg 粗脂肪，并分配到四个处理，CP350、CP400 、CP450 和 CP500。将体重在 16~18 g 范围内的 84 条鱼种随机分布在四个处理组中，每组 3 个重复。每天用指定的实验饮食喂鱼两次以达到明显的饱腹感。在 13 周的喂养试验结束时，饲喂CP400和CP450日粮的鱼的增重百分比（WG%）和比生长率（SGR）显着高于饲喂CP350和CP500日粮的鱼。CP400组代谢体重增长率（GRMBW）、日生长系数（DGC）和平均日生长量（ADG）较高，CP350组较低。内脏指数（VSI）、肝体指数（HSI）、胃体指数（GSI）和腹膜内脂肪比（IPFR）随着试验日粮粗蛋白含量的增加呈上升趋势，CP500处理达到最大值. CP400组全身组织的粗脂质和蛋白质含量最高，CP350组最低。在CP400组中观察到最大的肠蛋白酶活性。综上所述，