机构地区:[1]上海海洋大学水产与生命学院/农业部淡水水产种质资源重点实验室/上海市水产养殖工程技术研究中心,上海201306
出 处:《浙江大学学报(农业与生命科学版)》2014年第1期94-102,共9页Journal of Zhejiang University:Agriculture and Life Sciences
基 金:上海市教委科研创新项目(11YZ153);上海高校知识服务平台上海海洋大学水产动物遗传育种中心课题(ZF1206);上海市浦东新区科技发展基金创新资金(PKJ2012-N15);上海海洋大学博士启动基金(B-8812-10-0001-0190)
摘 要:在全植物基础饲料中添加不同水平的植酸酶,研究植酸酶对斑点叉尾鮰脊椎形态和非特异性免疫功能的影响.设6个等氮(37.50%粗蛋白)等能(17.00kJ/g总能)的实验组,分别是阴性对照(negative control,NC)组:在基础饲料中添加1%无机磷(CaHPO4);阳性对照(positive control,PC)组:NC组再添加1%无机磷(CaHPO4);4个植酸酶组:NC组中添加4种不同水平的植酸酶(250,500,1 000,2 000U/kg).每组设5个平行,对斑点叉尾鮰[(5.78±0.07)g/尾]进行为期60d的饲喂实验.结果表明:与NC组相比,添加植酸酶组增质量率显著提高(P<0.05),饲料系数显著降低(P<0.05);当植酸酶添加水平为1 000U/kg时,增质量率显著高于PC组(P<0.05)并达到最大值117.42%;植酸酶组鱼体蛋白保留率显著高于NC组(P<0.05),而与PC组差异无统计学意义(P>0.05);随着植酸酶添加水平的提高,鱼体磷保留率显著提高(P<0.05);在NC组中,明显发现鱼体脊椎中部出现弯曲和侧凸现象;当植酸酶添加水平为500U/kg时,肝溶菌酶(lysozyme,LSZ)活力显著高于NC组(P<0.05),而2 000U/kg植酸酶组头肾LSZ活力显著高于其他各组(P<0.05);当植酸酶添加水平大于1000U/kg时,头肾LSZ活力显著高于PC组(P<0.05);PC组肝超氧化物歧化酶(superoxide dismutase,SOD)活力显著高于其他组(P<0.05);当植酸酶添加水平为500 U/kg时,肝碱性磷酸酶(alkaline phosphatase,AKP)的活力与PC组无显著差异(P>0.05).综上所述,植酸酶的最适添加水平为1 000U/kg,在全植物饲料中添加植酸酶能促进斑点叉尾鮰的生长和鱼体蛋白保留,并能预防脊椎畸形和提高鱼体非特异性免疫相关酶活力.Various plant proteins such as soybean meal and canola meal were considered promising protein sources as substitutes for fishmeal . However , they would enhance the presence of anti-nutritional factors like phytate . Phytate ( myo-inositol-hexaphosphate phosphohydrolase) was the main storage form of phosphorus ( P) in plant proteins and not available for fish due to the lack of intestinal phytase for efficient phytate hydrolysis during digestion . Therefore , most of the phytate-P was excreted into the water which contributed to eutrophication effects . Phytase could be added to plant-based diets to hydrolyze non-digestible phytate into available-P during passing through the fish gut and improve the P availability , which reduced P excretion and its loss into the environment in fish diets . Furthermore , phytase could also improve protein digestibility by hydrolyze the form of phytate-protein complexes that are resistant to proteolytic digestion . In the present , most researches on phytase were directed toward determining its effect on bioavailability of nutrients ( P and protein) and the grow th performance of fish . Based on the fact that nutrients ( P and protein) were essential to maintain bone health and non-specific immune responses in fish , it was necessary to explore the effects of phytase on the bone health and non-specific immune responses in fish . This experiment was conducted to evaluate the effects of different levels of liquid phytase on vertebral shapes and non-specific immune responses in channel catfish ( Ictalurus punctatus ) . Six isonitrogenous ( 37.50% crude protein) and isocaloric ( 17.00 kJ/g gross energy) diets were formulated , a negative control ( NC) diet :a basal diet was supplemented with 1% dicalcium phosphate ( CaHPO4 ) , a positive control ( PC ) diet : the NC diet was supplemented with another 1% dicalcium phosphate (CaHPO4) ,in addition ,four phytase supplementation groups:the NC diets with graded levels ( 250 , 500 , 1 000 ,
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