酸制剂对罗非鱼生长和饲料利用的影响

Effects of acid supplements on growth and feed utilization in tilapia Oreochromis niloticus×O.aureus

为考察不同酸制剂对奥尼罗非鱼幼鱼生长和饲料利用的影响,在基础饲料(对照组)中分别添加0.3%磷酸、富马酸、柠檬酸和乳酸,饲养奥尼罗非鱼幼鱼9周(初始平均体重约1.9g)。结果表明,添加0.3%柠檬酸和乳酸饲料组的罗非鱼特定生长率显著高于对照组和添加富马酸组(P<0.05);磷酸组、柠檬酸组和乳酸组的饲料效率较对照组有提高趋势(P>0.05),乳酸组的饲料效率显著高于富马酸组(P<0.05);柠檬酸组和乳酸组鱼体水分含量显著高于富马酸组(P<0.05),体粗蛋白、粗脂肪和灰分含量在组间差异不显著(P>0.05);胃蛋白酶活性在富马酸组显著低于其它饲料组(P<0.05),肠淀粉酶活性在柠檬酸组和乳酸组显著高于对照组(P<0.05);肝脏代谢酶活性在柠檬酸组和乳酸组显著高于对照组、磷酸组和富马酸组(P<0.05),相应地,柠檬酸组和乳酸组罗非鱼血清甘油三酯含量显著高于对照组(P<0.05)。结果说明,添加0.3%柠檬酸和乳酸能显著促进罗非鱼幼鱼生长,提高饲料的利用,富马酸降低罗非鱼对饲料的利用。

A 9-week feeding trial was conducted to investigate effects of different dietary acid supplements on growth performance in juvenile hybrid tilapia Oreochromis niloticus×O.aureus (average body weight was about 1.9g). 5 test diets were applied for triplicate tanks and 15 fish was stocked randomly in each tank. Feeding rate was 6% of wet body weight. No acid supplement was added in basal diet which was applied as control, 0.3% of phosphoric acid, fumaric acid, citric acid, lactic acid were added in basal diet, respectively. The results showed that specific growth rate of fish fed diet with citric acid and lactic acid were significantly higher than those of fish fed basal diet and diet with fumaric acid (P<0.05). Feed efficiency in fish fed diets with phosphoric acid, lactic acid and citric acid was higher than that of fish fed basal diet, but differences were not significant (P>(0.05)). However, significantly higher feed efficiency was observed in fish fed diet with lactic acid than that of fish fed diet with fumaric acid (P<0.05). The content of body moisture in fish fed diet with lactic acid was significantly higher than that of fish fed diet with fumaric acid (P<0.05), while no significant differences were observed in whole body protein, lipid and ash among treatments (P>0.05). The activity of pepsin in fish fed diet with fumaric acid was significantly lower than those of fish fed with other diets. The intestinal amylase activities in fish fed diets with citric acid and lactic acid were significantly higher than that of fish fed basal diet (P<0.05). Significantly higher activities of hepatic lipogenetic enzymes were observed in fish fed diet with lactic acid and citric acid than those of fish fed other three diets (P<0.05). Accordingly, serum triglyceride concentration in fish fed diets with citric acid and lactic acid was increased significantly. The results suggested that 0.3% citric acid and lactic acid supplements can significantly improve growth performance in juvenile hybrid tilapia, while, fumaric acid supplement reduces feed utilization.