黄斑篮子鱼幼鱼适宜投喂频率的研究

为探明黄斑篮子鱼(Siganus oramin)幼鱼适宜投喂频率,选择体重为(1.80±0.08)g的幼鱼进行养殖试验。试验设计5个组(F1、F2、F3、F4、F5组),投喂频率分别为1(06:00),2(06:00、18:00),3(06:00、12:00、18:00),4(06:00、10:00、14:00、18:00)和5次/d(06:00、09:00、12:00、15:00、18:00),每组设3个平行,共计15个养殖桶,每桶随机放50尾试验鱼。试验观察不同投喂频率下黄斑篮子鱼幼鱼生长性能、饲料利用、形体指标、肌肉成分及肠道消化酶活性的变化情况。试验周期为60 d。结果显示:1)各组试验鱼终末体重、增重率、摄食率、特定生长率和蛋白质效率均随投喂频率增加呈上升趋势,F3、F4、F5组终末体重、增重率和特定生长率显著高于F1、F2组(P<0.05),饲料系数显著低于F1、F2组(P<0.05),3组间差异不显著(P>0.05);其中F3组饲料系数最低,蛋白质效率最高。2)F3、F4、F5组肝体指数显著低于F2组(P<0.05),脏体指数显著低于F1、F2组(P<0.05),各组间肥满度差异不显著(P>0.05)。3)随着投喂频率的增加,试验鱼肌肉中粗蛋白质、粗脂肪、粗灰分含量逐渐上升,水分含量逐渐下降,F3、F4、F5组肌肉中粗脂肪、粗灰分含量显著高于F1组(P<0.05),水分含量显著低于F1、F2组(P<0.05),3组间上述指标差异不显著(P>0.05)。4)各组肠道中胃蛋白酶、淀粉酶活性随投喂频率增加呈下降趋势,胰蛋白酶、脂肪酶活性先降后升,F1、F2组各消化酶活性显著高于F3、F4、F5组(P<0.05),F3、F4、F5组间差异不显著(P>0.05)。综合上述指标并考虑养殖成本,建议黄斑篮子鱼幼鱼适宜投喂频率为3次/d。

Optimal Feeding Frequency for Juvenile Siganus oramin

In order to ascertain the optimal feeding frequency for juvenile Siganus oramin,the fish with body weight of(1.80±0.08)g were selected for the feeding test.In this test,five groups(F1,F2,F3,F4 and F5 groups)were designed with different feeding frequencies of 1(06:00),2(06:00,18:00),3(06:00,12:00 and 18:00),4(06:00,10:00,14:00 and 18:00)and 5 meals per day(06:00,09:00,12:00,15:00 and 18:00),respectively,and 3 replicates per group,total 15 breeding barrels and 50 fish in each barrel.The changes in growth performance,feed utilization,body indexes,muscle composition and intestinal digestive enzyme activities of juvenile Siganus oramin were observed.The results showed as follows:1)the final body weight,weight gain rate,feed intake rate,specific growth rate and protein efficiency ratio of the test fish increased with the increase of feeding frequency.Final weight,weight gain rate and specific growth rate of F3,F4 and F5 groups were significantly higher than those of F1 and F2 groups(P<0.05),and feed conversion ratio was significantly lower than that of F1 and F2 groups(P<0.05),and was no significant difference among the three groups(P>0.05).F3 group had the lowest feed conversion ratio and the highest protein efficiency ratio.2)Hepatosomatic index of F3,F4 and F5 groups was obviously lower than that of F2 group(P<0.05),viscerosomatic index of F3,F4 and F5 groups was obviously lower than that of F1 and F2 groups(P<0.05),and there was no significant difference in condition factor among all groups(P>0.05).3)With the increase of feeding frequency,the crude protein,crude fat and ash contents in the muscle of the test fish gradually increased,while the moisture content gradually decreased.Crude fat and ash contents of F3,F4 and F5 groups were significantly higher than those of F1 group(P<0.05),while the moisture content was significantly lower than that of F1 and F2 groups(P<0.05),and was no significant difference among the three groups(P>0.05).4)Pepsin and amylase activities in test fish intestine decreased with the increase of feeding frequency,trypsin and lipase activities decreased first and then increased,and the digestive enzyme activities of F1 and F2 groups were significantly higher than those of F3,F4 and F5 groups(P<0.05),and were no significant difference among the latter(P>0.05).Based on above results and considering the feeding cost,it is suggested that the optimal feeding frequency for Juvenile Siganus oramin should be 3 meals per day.