不同糖源对拟穴青蟹仔蟹的生长、体成分及消化酶的影响

在水温26~30℃,盐度18~22条件下,初始体质量(0.012±0.000)g的拟穴青蟹仔蟹饲养在底铺1~2 cm细沙、边缘放5 cm^2瓦片的塑料水桶(直径20 cm,水深20 cm)中,投喂以葡萄糖、蔗糖、糊精、木薯淀粉、玉米淀粉、糊化木薯淀粉和糊化玉米淀粉为糖源的7种等氮等能饲料,养殖3周,研究不同糖源对拟穴青蟹仔蟹生长、体组成及消化酶活性的影响。试验结果显示,不同糖源显著影响拟穴青蟹仔蟹的生长性能(P<0.05);质量增加率和特定生长率依次为糊化木薯淀粉>糊化玉米淀粉>木薯淀粉>玉米淀粉>糊精>蔗糖>葡萄糖;葡萄糖试验组的成活率显著低于其他各组(P<0.05)。不同糖源对拟穴青蟹仔蟹体组成中粗蛋白和粗脂肪含量影响显著(P<0.05),对仔蟹的水分和灰分含量影响不显著(P>0.05);不同糖源对3种消化酶活性影响显著(P<0.05)。拟穴青蟹仔蟹对大分子糖源的生物利用度要大于小分子糖源。在本试验的研究条件下,7种常见糖源中糊化木薯淀粉是拟穴青蟹仔蟹的最适糖源。

Effects of Different Dietary Carbohydrate Sources on Growth Performance,Body Composition and Digestive Enzyme Activities of Juvenile Green Crab Scylla paramamosain

Juvenile green crab Scylla paramamosain with average body weight of(0.012±0.000)g were reared in plastic buckets(20 cm in diameter and 20 cm in depth)with 1-2 cm fine sand and 5 cm^2 tiles at bottom and fed diets containing seven carbohydrate(CBH)sources(glucose,sucrose,dextrin,tapioca starch,corn starch,gelatinized tapioca starch,and gelatinized corn starch)for 3 weeks to investigate the effects of dietary CBH sources on growth performance,body composition and digestive enzyme activities of green crab.The results showed that the growth performance of the juvenile was significantly influenced by different CBH sources(P<0.05),the maximal weight gain rate(WGR)and specific growth rate(SGR)in the green crab fed gelatinized tapioca starch,significantly higher than those in other groups(P<0.05)and with the descending order of WGR and SGR as:gelatinized cassava starch>gelatinized corn starch>cassava starch>corn starch>dextrin>sucrose>glucose.The minimal survival ratio(SR)was observed in glucose group,significantly lower than that in the other groups(P<0.05).The body composition analysis indicated that dietary CBH sources had significant effects on body ether extract content and body protein contents(P<0.05),without significant differences in moisture,and ash content(P>0.05).There were significant effects of different dietary CBH sources on digestive enzyme activities in the green crab juveniles(P<0.05),indicating that green crab had higher bioavailability of macromolecule carbohydrate sources than that of micromolecule CBH sources.It is concluded that gelatinized cassava starch is the optimal carbohydrate sources for green crab juveniles.