不同循环饥饿投喂模式对许氏平鲉生长和体成分的影响

Effect of Different Cyclic Starvation and Refeeding Regimes on Growth and Body Compositions in Black Rockfish Sebastes schlegelii

为探究不同循环饥饿投喂模式下许氏平鲉的补偿生长和体成分的变化,分别采用每日投喂(对照组)、饥饿2 d投喂1 d、饥饿2 d投喂2 d、饥饿2 d投喂3 d、饥饿2 d投喂4 d和饥饿2 d投喂5 d的循环饥饿投喂模式,对初始体长(10.25±0.74)cm、体质量(16.77±2.72)g的许氏平鲉幼鱼进行为期67 d的养殖试验。试验结果显示:饥饿2 d投喂5 d试验组的终末体质量、质量增加率、特定生长率均最高,表现为超补偿生长;饥饿2 d投喂4 d组的终末体质量、质量增加率和特定生长率与对照组差异不显著(P>0.05),表现为完全补偿生长;饥饿2 d投喂1 d、饥饿2 d投喂2 d和饥饿2 d投喂3 d试验组的终末体质量、质量增加率和特定生长率均显著低于对照组(P<0.05),表现为不能补偿生长。各组间的饲料效率、肝体指数和肥满度差异不显著(P>0.05),但对照组的脏体指数显著高于循环饥饿投喂组(P<0.05)。与对照组相比,循环饥饿投喂组(除饥饿2 d投喂5 d试验组外)的鱼体粗脂肪含量显著降低(P<0.05),粗蛋白质和灰分含量各组间差异不显著(P>0.05)。饥饿2 d+投喂5 d的循环饥饿投喂模式,获得了超补偿生长,投喂时间比对照组缩短29.85%,为本试验条件下最佳投喂模式。

A 67-day feeding trial was conducted to determine compensatory growth and body composition after experiencing cycles of starvation and re-feeding in juvenile black rockfish Sebastes schlegelii with initial body length of(10.25±0.74)cm and body weight of(16.77±2.72)g.Six feeding regimes were designed as follows:the control group of fish fed daily(S0),and other five groups that were subjected to 2 days of starvation followed by 1 to 5 days of feeding to satiation,i.e.S2F1(starved for 2 d,then fed 1 d),S2F2(starved 2 d,then fed 2 d),S2F3(starved 2 d,then fed 3 d),S2F4(starved 2 d,then fed 4 d)and S2F5(starved 2 d,then fed 5 d).The results showed that there were the maximal final body weight,weight gain rate and specific growth rate in group S2F5,showing an over-compensatory growth.The final body weight,weight gain rate and specific growth rate were not significantly different in group S2F4from those in the control group(P>0.05),showing a completely compensatory growth.The final body weight,weight gain rate and specific growth rate in groups S2F1,S2F2and S2F3were significantly lower than those in the control group(P<0.05),showing a non-compensatory growth.There were no significant differences in feed conversion efficiency,hepatosomatic index and condition factor among all groups(P>0.05),but the viscerosomatic index was significantly higher in the control group than that in the feeding regime groups(P<0.05).Compared with the control group,the body lipid content(except group S2F5)was significantly decreased(P<0.05),while the body protein and ash contents were not significantly different among all groups(P>0.05).The cyclic feeding regime of starved 2 d,then fed 5 d led to over-compensatory growth,and the feeding time was shortened by 29.85%compared with the control group,which is the best feeding mode under the experimental conditions.