摘要
实验以初始体质量为（53.65±0.05）g的吉富罗非鱼幼鱼为研究对象,随机分为7个处理组（每个处理3个重复,每个重复14尾鱼）,分别饲喂亮氨酸（Leu）水平为1.11%、1.51%、1.90%、2.29%、2.69%、3.08%和3.48%的7种等氮等能（粗蛋白32%）的半精制饲料56 d,旨在评价吉富罗非鱼对Leu的最适需求量。结果表明,以增重率（WGR）、特定生长率（SGR）、饲料系数（FCR）为评价指标,通过二次回归分析可知,在投饲率为4%~6%时,罗非鱼饲料中适宜的Leu为2.28%~2.33%。随饲料Leu水平的增加,罗非鱼全鱼粗蛋白和粗脂肪、肌肉粗蛋白和粗脂肪均呈先升后降的趋势,而全鱼和肌肉水分差异不显著。罗非鱼胃蛋白酶、肠蛋白酶、肠脂肪酶、肠淀粉酶和Na＋-K＋-ATP酶的活性也随饲料Leu水平的升高呈先升后降趋势,除肠脂肪酶活性在2.69%水平组最高外,其他指标均在2.29%水平组达到最大值。同时,罗非鱼肠道表皮生长因子（EGF）、肠道表皮生长因子受体（EGFR）、血清超氧化物歧化酶（SOD）、血清溶菌酶（LZM）和血清碱性磷酸酶（AKP）也均在Leu为2.29%水平组达到最大值。研究表明,罗非鱼（50~200 g）饲料Leu的最适需求量为2.28%~2.33%（占饲料蛋白的7.11%~7.26%）,该Leu水平能显著促进肠粘膜的发育,增强胃肠消化、吸收能力和机体非特异性免疫能力,从而促进罗非鱼的生长和饲料的转化。
To determine dietary leucine （Leu） requirement of tilapia （ GIFT Oreochromis niloticus）, tilapias with an initial body weight（53.65 ± 0.05）g were randomly divided into seven treatments in triplicates with 14 fishes per repetition. Seven isonitrogenous （crude protein 32% ） and isoenergetic semi-purified diets containing different levels（ 1.11% ,1.51% ,1.90% ,2.29% ,2.69% ,3.08% and 3.48% ） of dietary Leu were fed to tilpias at the feeding rate of 4% -6% for 56 d. Quadratic regression analysis showed that the optimal dietary Leu levels of tilapia were 2.28 % -2.33 % base on weight gain rate （WGR）, specific growth rate（SGR） , feed conversion ratio（FCR） o With an increase of dietary Leu level, the crude protein and crude lipid content of whole body and muscle initially increased and then decreased, but there were no significant differences in moisture content of muscle. With an increase of dietary Leu level, activities of intestinal amylase activity,intestinal protease ,Na ~ -K ~ -ATPase initially increasing and then decreased, and the lipase activity get maximum at 2.69% level and the others got maximum at 2.29% level. With the increase of dietary Leu level, the concentrations of EGF and EGFR, and the activities of SOD, LZM and AKP also initially increased and then decreased, all got maximum at 2.29% level. In conclusion, the optimal dietary Leu level for 50 -200 g GIFT tilapia was 2.28% -2.33% （or 7. 11% -7.26% of dietary protein）. This Leu level can significantly promote the development of intestinal mucosa, enhance gastro-intestinal digestion and absorption capacity, thus improve the body＇ s nonspecific immunity, and then promote the growth and utilization of tilapia.
出处
《水产学报》
CAS
CSCD
北大核心
2014年第10期1778-1785,共8页
Journal of Fisheries of China
基金
国家罗非鱼现代产业技术体系建设专项(CARS-49)
公益性行业(农业)科研专项(201003020)
重庆市自然科学基金(cstc2011jjA80021)
关键词
吉富罗非鱼
亮氨酸
需求量
酶活性
GIFT Oreochromis niloticus
leucine
requirement
enzymeactivity
