摘要
通过胃排空试验与养殖试验研究了不同投喂频率对尼罗系吉富罗非鱼幼鱼的胃排空、生长性能以及体组成的影响。在试验开始时,观测尼罗系吉富罗非鱼幼鱼的胃内饲料排空情况,胃排空试验结果表明,胃排空率的最佳描述为平方根函数,胃内饲料在饱食投喂后15 h左右完全排空,达到投喂前水平,80%胃排空为9 h,也就是投喂后大约9 h恢复食欲。360尾试验鱼(初始体质量3.72 g)以不同的投喂频率(1 d 4次、1 d 3次、1 d 2次、2 d 4次、2 d 3次、2 d 2次)分组,每组设立3个平行组,随机养殖于18个网箱中,每箱养殖20尾鱼,按饱食量投饲膨化饲料。养殖期为6周。尼罗系吉富罗非鱼幼鱼在投喂频率为1 d 4次、1 d 3次和1 d 2次时特定生长率和饲料效率显著高于投喂频率为2 d 4次、2 d 3次和2 d 2次时(P<0.05);投喂频率为1 d 2次、2 d 4次、2 d 3次和2 d 2次时其摄食量显著低于1 d 4次和1 d 3次时(P<0.05)。随着投喂频率降低,鱼体水分含量逐步上升,脂肪和蛋白质含量逐步下降,其中1 d 4次、1 d 3次组鱼与2 d 2次组鱼有显著性差异(P<0.05)。各投喂频率组间的肝体指数无显著性差异(P>0.05)。3.7～48.0 g尼罗系吉富罗非鱼幼鱼的适宜投喂频率为1 d 2次,较2 d 2次、2 d 3次和2 d 4次时明显提高了生长速度和饲料效率,较1 d 3次、1 d 4次摄食量显著降低。2种试验结果较为一致。
A 6-week feeding experiment was conducted to determine the optimum feeding frequency for gastric evacuation,growth performance and body composition of the juvenile genetic improved farmed tilapia strain of Nile Tilapia（Oreochromis niloticus）（GIFT strain of Nile tilapia）.At the start of the feeding trial,gastric evacuation rate of the fish was monitored after feeding to visual satiety.Gastric evacuation of the fish was best fitted with square root model.It was estimated that gastric feed contents gradually decreased and reached the pre-feeding level within 15 h and 80% evacuation would require 9 h,which suggested corresponded to the return of appetite.Six replicate groups of the 360 fish（initial weight 3.72 g）were fed to visual satiety puffed feed at different feeding frequencies（four meals a day,three meals a day,two meals a day,four meals every 2 days,three meals every 2 days and two meals every 2 days）.As feeding frequency decreased,the weight gain and feed efficiency of the juvenile gradually decreased.The specific growth ratios（SGR）of fish fed four meals a day,three meals a day and two meals a day were significantly higher than those of four meals every 2 days,three meals every 2 days and two meals every 2 days（P0.05）.The feed intakes of fish fed two meals a day,four meals every 2 days,three meals every 2 days and two meals every two days were significantly lower than those of three meals a day and four meals a day（P0.05）.As feeding frequency decreased,moisture contents of fish body increased and the contents of fat and protein decreased gradually,and there were significant difference between the fish fed four meals a day,three meals a day and the fish fed two meals every 2 days.Hepatosomatic indices of fish were not significantly different between all test groups.It is concluded that two meals a day is more effective than other feeding frequencies for improving growth performance or feed efficiency of juvenile GIFT strain of Nile tilapia from 3.7 to 48.0 g.Gastric evacuation is a simple and convenient method to evaluate optimum feeding frequency of juvenile GIFT strain of Nile tilapia.
出处
《水产学报》
CAS
CSCD
北大核心
2011年第11期1677-1683,共7页
Journal of Fisheries of China
基金
广西科技厅基金计划项目(09321022)
关键词
尼罗系吉富罗非鱼
投喂频率
胃排空
生长性能
体组成
GIFT strain of Nile tilapia
feeding frequency
gastric evacuation
growth benefit
body composition
