不同商品饲料对生长、体色及肝脏组织结构的影响

本试验评估了(Ictalurus punctatus)主产区4种商品颗粒饲料(分别记为S1、S2、S3和S4,其中S4为膨化饲料,其他均为颗粒饲料)和自行设计的颗粒饲料(记为S5)对试验阶段生长性能、体色变异、肝胰脏组织结构及形态指标的影响。7周的饲喂试验结果显示:饲料蛋白含量为38%的S4膨化饲料可明显的提高养殖鱼的体重,平均增重率为262.6%,但存活率较低,仅为72.3%;而喂养S5饲料组的增重率为168.89%,且存活率为92.4%,高于其他饲料组。养殖结束后,不同试验组的肥满度、脏体比有所差异,但均未达到显著性水平(P>0.05)。投喂S2饲料组养殖鱼体体色发白比较明显,体色异常比例高达91%;S4饲料组养殖后体色发白也比较明显,体色异常比例为72.3%;对背部黑色素扫描研究进一步证实饲喂S2饲料和S4饲料的黑色素细胞发生了变化,黑色素细胞边缘变得模糊,而自配S5饲料的黑色素细胞树突状分支较多;饲喂S4饲料组的背部斑点比例为12.15%,而S2饲料组的背部斑点比例为26.38%,自配S5饲料组的背部斑点比例为35.69%,S4饲料组的斑点比例明显较低。

Effects of different commercial feeds on growth,body color and live tissue structure of channel catfish(Ictalurus punctatus)

This experiment was conducted to evaluate effects of four kinds of commercial channel catfish feeds(named as S1~S4,S4 was extruded feed,and others were pellet feeds) from Changyang area and one kind of feed formulated by ourselves(S5) on growth performance,body color variation and histological structure of hepatopancreas and morphology of channel catfish.7-week feeding trial showed:S4 containing 38% protein can significantly improve juvenile′s weight,the average growth rate was 262.6%,but the survival rate was only 72.3%;the average growth rate of fish fed with S5 feed was 168.89%,and the survival rate was 92.4%,which was the highest of all groups.In the end of feeding trial,fullness,viscerosomatic index(VSI) of channel catfish fed with different feeds had some difference,but not significant(P>0.05).For body color,fish fed with S2 turned white obviously,and body color abnormal rate was 91%;Meanwhile,fish fed with S4 was also quite noticeable,body color abnormal rate was 72.3%;The melanoma cells have changed,and melanophore distribution become blurred when the back epidermal skin of fish fed with S4 feed and S2 feed was scanned.However,the melanoma cells of skin of fish fed with S5 feed had more dendritic branches than S4 and S2.