This study aimed to examine the effects of dietary tuna hydrolysate supplementation on feed intake, growth, feed utilization and health status of Asian sea bass. Experimental diets included a high fish meal-based diet (HFM diet) containing 45% of fish meal, a low fish meal-based diet (LFM diet) in which 55% of fish meal protein was replaced with soybean meal and the LFM diet coated with 2.5% tuna hydrolysate (LFM + TH diet). Fish were fed diets for 8 weeks. Growth rate, feed intake, feed efficiency, protein efficiency ratio, nitrogen retention, intraperitoneal fat and serum albumin of fish-fed LFM + TH diet were significantly higher than those of fish-fed LFM diet (p < 0.05). No significant differences in carcass chemical compositions, serum cholesterol, triglyceride, aspartate aminotransferase, lysozyme activity, superoxide dismutase and trypsin and lipase activities were found in hepatopancreas and anterior intestine among the dietary treatments. Fish-fed LFM + TH diet displayed a longer length of distal intestine villi than those of fish-fed LFM + TH diet. No histopathological changes in the liver were observed in this study. The results suggest that dietary supplementation of 2.5% tuna hydrolysate is sufficient to enhance the diet palatability, which can increase the replacement levels of fish meal protein with soybean meal up to 55% in a low fish meal soybean meal-based diet without negative impacts on feed intake and growth performance of juvenile Asian sea bass.

中文翻译：

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日粮中添加金枪鱼水解物对亚洲鲈鱼（Lates calcarifer）采食量、生长性能、饲料利用和健康状况的影响

本研究旨在检查日粮中添加金枪鱼水解物对亚洲鲈鱼的采食量、生长、饲料利用和健康状况的影响。实验性日粮包括含 45% 鱼粉的高鱼粉日粮（HFM 日粮）、以豆粕替代 55% 鱼粉蛋白的低鱼粉日粮（LFM 日粮）和 LFM 日粮包衣含 2.5% 金枪鱼水解物（LFM + TH 饮食）。鱼被喂食 8 周。鱼饲LFM+TH日粮的生长速度、采食量、饲料效率、蛋白质效率比、氮保留、腹腔内脂肪和血清白蛋白均显着高于鱼饲LFM日粮（p < 0.05)。不同日粮处理在肝胰腺和前肠的胴体化学成分、血清胆固醇、甘油三酯、天冬氨酸氨基转移酶、溶菌酶活性、超氧化物歧化酶和胰蛋白酶和脂肪酶活性没有显着差异。鱼饲 LFM + TH 日粮的远端肠绒毛长度比鱼饲 LFM + TH 日粮长。在本研究中未观察到肝脏的组织病理学变化。结果表明，日粮中添加 2.5% 的金枪鱼水解物足以提高日粮的适口性，在以豆粕为基础的低鱼粉日粮中，可以将鱼粉蛋白与豆粕的替代水平提高 55%，而不会对鱼粉产生负面影响。幼年亚洲鲈鱼的采食量和生长性能。