饲料铁水平对方格星虫稚虫生长性能、体成分、酶活性及组织铁含量的影响

Effects of Dietary Iron Level on Growth Performance,Body Composition,Enzyme Activity and Tissue Iron Content of Juvenile Peanut Worm,Sipunculus nudus Linnaeus

本试验旨在探讨饲料中微量元素铁水平对方格星虫稚虫生长性能、体成分、酶活性及组织铁含量的影响。选取平均体重为(16.11±0.09)mg的7 200条方格星虫稚虫,随机分为6组,每组3个重复,每个重复400条,分别饲喂铁水平为11.2、42.5、61.3、115.6、283.7、482.1 mg/kg的饲料56 d。结果表明:饲料铁水平对方格星虫稚虫养殖的成活率、增重率和特定生长率都有显著影响(P<0.05),随着饲料铁水平增加,均呈先升后降的趋势;体成分方面,饲料铁水平仅对方格星虫稚虫体粗脂肪含量有显著影响(P<0.05),随着饲料铁水平的升高体粗脂肪含量呈先增高后降低趋势,但各组体粗蛋白质、水分和粗灰分含量无显著差异(P>0.05);酶活性方面,饲料铁水平对过氧化氢酶活性有显著影响(P<0.05),随着饲料铁水平的升高先呈逐渐升高趋势后趋于平稳;此外,铁元素能被方格星虫吸收,并储存于虫体之中。以增重率为评价指标,方格星虫饲料最佳铁水平为115.6 mg/kg;以虫体铁含量为评价指标,通过折线模型回归分析,饲料铁水平为118.65 mg/kg时虫体铁含量(233.85μg/g)最大。

This trial was conducted to investigate the effects of dietary iron level on growth performance,body composition,enzyme activity and tissue iron content of juvenile peanut worm,Sipunculus nudus Linnaeus.Sipunculus nudus juveniles with average body weight of（ 16. 11 ± 0. 09） mg were randomly divided into 6groups with 3 replicates per group and 400 juveniles per replicate,and fed diets with six iron levels（ 11.2,2.5,61.3,115.6,283.7,482.1 mg / kg,respectively） for 56 d. The results showed that the dietary iron levels had significant effects on weight gain rate（ W GR）,specific growth rate（ SGR） and survival ratio（ SR） of Sipunculus nudus（ P 〈0.05）. W ith the increasing of dietary iron level,W GR,SGR and SR trended to increase firstly and then decrease. The results of body composition analysis showed that dietary iron level had significant effects on body ether extract content（ P 〈0.05）. The body ether extract content trended to increase firstly and then decrease with the increasing of dietary iron level. No significant differences were observed in body moisture,crude protein and ash contents of Sipunculus nudus（ P 〉0. 05）. Dietary iron level significantly affected catalase（ CAT） activity of Sipunculus nudus（ P 〈0.05）. W ith the increasing of dietary iron level,the CAT activity was firstly increased and then tended to be stable. And dietary iron could be absorbed by Sipunculus nudus. In conclusion,the best dietary iron level which can acquire the best W GR is 115.6 mg / kg,and the dietary iron level 118.65 mg / kg can acquire the highest body iron content（ 233.85 μg / g）.