饲料中添加水解鱼蛋白对半滑舌鳎稚鱼生长及生理生化指标的影响

试验研究了饲料中添加不同水平(0%、20%、40%和60%)的水解鱼蛋白(Fish potein hdrolysate,FPH)对半滑舌鳎(Cynoglossus semilaevis Günther)稚鱼生长及生理生化指标的影响。28d饲养实验结束后,对试验鱼生长指标、鱼体消化酶活性、碱性磷酸酶(AKP)及肠道发育情况进行分析。结果显示:实验鱼的存活率为64.44%—78.88%,其中20%与40%添加组存活率显著高于其他两组(P0.05);实验鱼的特定生长率(SGR)随饲料中FPH添加水平升高呈下降趋势,20%添加组特定生长率最高,显著高于其他3组(P0.05),且60%添加组与对照组(FM)之间无显著差异(P0.05);各试验组鱼体消化酶(脂肪酶、淀粉酶、胃蛋白酶和胰蛋白酶)的比活力在14d与28d时的强弱关系不一致。鱼体碱性磷酸酶比活力大小依次为:20%组40%组对照组60%组,各组间差异均显著(P0.05);半滑舌鳎肠道微绒毛长度和黏膜厚度均以20%添加组为最优,显著优于其他3组(P0.05)。以上结果表明,在实验条件下,饲料中FPH的添加水平为20%时,能提高半滑舌鳎稚鱼的存活率及生长性能,并增强其对营养物质的吸收能力。

EFFECT OF FISH PROTEIN HYDROLYSATE LEVELS ON GROWTH PERFORMANCE AND BIOLOGICAL AND PHYSIOLOGICAL PARAMETERS IN TONGUE SOLE (CYNOGLOSSUS SEMILAEVIS G(U)NTHER, 1873) POST-LARVAE

This study evaluated the effects of fish protein hydrolysate inclusion in the diet of tongue sole (Cynoglossus semilaevis Gunther, 1873) post-larvae on growth performance, the activities of alkaline phosphatase (AKP) and the digestive enzymes: pepsin, trypsin, iipase and amylase and intestine development in the fish. Four experimental diets were formulated by supplementing 0% (FM), 20% (FPH-20), 40% (FPH-40) and 60% (FPH-60) of FPH in the diet. Each diet was randomly assigned to triplicate groups of fish, and each group was stocked with 60 tongue sole post-larvae (30 days post-hatching, with an initial dry weight of 6.47±0.38 mg) in 12 fiberglass tanks (50 cm×40 cm×20 cm). Fish were fed four times daily (05:00, 10:00, 15:00 and 21:00) to visual satiation for 28 days. During the feeding trial, water temperature and salinity were maintained at (22±1℃) and 30-32, respectively. At the end of the 28-day growth experiment, survivals of the fish were relatively high and ranged from 64.44% to 78.88%. Fish fed diets with 20% and 40% FPH showed significantly higher survival rates than other two groups (P<0.05). Compared to the control, 20% FPH supplementation in the diet improved growth of the tongue larvae while high dose of FPH depressed that concerning the values of specific growth rate (SGR); the activities of digestive enzymes, such as lipase, amylase, pepsin and trypsin showed no obvious trends among all treatments between 14 and 28 d, respectively; the AKP activity in all groups were ordered as follows (P<0.05): 20% FPH>40% FPH>0% FPH>60% FPH; fish fed the diet with 20% FPH showed significantly higher intestinal villus and thicker mucosa than the other three groups (P<0.05). In this study, the diet with 20% of the FPH gave the best results in terms of growth, survival and intestinal development in tongue sole post-larvae,indicating FPH had a nutritional value equivalent to fish meal (FM).