桑叶对罗非鱼生长性能、脂质代谢和肌肉品质的影响

摘要

试验选取云南、陕西、重庆所产桑叶，在基础饲料中分别添加0（对照组）、5％、10％不同来源桑叶粉，配制成7种等能等氮的试验饲料，在室内淡水循环养殖系统中饲喂平均体重为9g的吉富罗非鱼8周，以研究桑叶对罗非鱼生长性能、脂质代谢和肌肉品质的影响。每组设3个重复，每个重复40尾鱼。结果表明：桑叶来源、添加水平以及二者的交互作用对罗非鱼的末重、特定生长率（ SGR ）、蛋白质效率（ PER ）、饲料系数（ FCR ）和摄食率（ FR ）均无显著影响（ P＞0．05）。各试验组罗非鱼的脏体指数（ VSI）、肝体指数（ HSI）以及血清中总胆固醇（ CHO）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）含量均显著低于对照组（P＜0．05），且随桑叶添加水平的增加上述指标有不同程度地降低（P＞0．05或P＜0．05）。对于不同来源的桑叶，均表现为10％组罗非鱼的血清高密度脂蛋白胆固醇（ HDL-C）含量及HDL-C/CHO和HDL-C/LDL-C最高，肌肉pH降低值、滴水损失和全血葡萄糖含量最低，且与对照组和5％组的差异达到显著水平（ P＜0．05）。各组罗非鱼的肥满度（ CF），鱼体水分、粗蛋白质、粗脂肪、粗灰分含量以及肌肉熟肉率无显著差异（ P＞0．05）。由此可见，饲料中添加10％的桑叶不会影响罗非鱼的生长性能，同时可有效调节罗非鱼的脂质代谢，改善其肌肉品质。%In order to study effects of dietary mulberry leaves on growth performance, fat metabolism and mus-cle quality of tilapia ( Oreochromis niloticus) , 3 mulberry leaves were collected from Yunnan, Shaanxi and Chongqin. A basal diet was supplemented with 0 ( control group) , 5% and 10% mulberry leaf powder from different sources to formulate 7 isonitrogenous and isoenergetic experimental diets. Genetically improved farmed tilapia ( GIFT) with the average body weight of 9 g were used as experimental animal, and were randomly di-vided into 7 groups with 3 replicates per group and 40 fish per replicate. Fish in each group were fed one exper-imental diet for 8 weeks in a recirculated filtered rearing system. The results showed as follows: source and supplemental level of mulberry leaves and their interaction had no significant differences in final body weight, specific growth rate ( SGR) , protein efficiency ratio ( PER) , feed conversion ratio ( FCR) and feeding rate ( FR) ( P>0.05) . The viscerosomatic index ( VSI) , hepatosomatic index ( HSI) and the contents of total cho-lesterol ( CHO) , triglyceride ( TG) and low density lipopretein cholestorol ( LDL-C) in experimental groups were significantly lower than those in control group ( P<0.05) , and those indices had different degrees of de-crease with the supplemental level of mulberry leaves increasing (P>0.05 or P<0.05). For mulberry leaves from different sources, the fish in the 10% group all had the highest values of serum high density lipoprotein cholesterol ( HDL-C ) content, HDL-C/CHO and HDL-C/LDL-C and the lowest values of muscle pH de-creased value, drop loss and blood glucose content, and the differences in those indices reached significance level between 10% group and control group and 5% group ( P<0.05) . There were no significant differences in condition factor ( CF) , the contents of moisture, crude protein, crude lipid and crude ash in whole body, and the muscle cooking rate among all groups ( P>0.05) . The results suggest that dietary mulberry leaves can not affect the growth performance of tilapia, but can effectively regulate the fat metabolism and improve the muscle quality of tilapia.