Effects Of Feeding Frequency On Gastric Evacuation, Growth Performance And Body Composition Of Juvenile Darkbarbel Catfish(Pelteobagrus Vachelli Richardson)

A6-week experiment was conducted to determine the optimum feeding frequency for gastric evacuation, growth performance and body composition of juvenile Darkbarbel catfish (Pelteobagrus vachelli Richardson). At the start and end of the feeding trial, gastric evacuation rate of the fish was monitored after feeding. Gastric evacuation of fish was best fitted with square root model. By the square root model of GER, it was estimated that evacuation would require36—40h reaching the pre-feeding level and95%evacuation would require32—36h, which suggested the return of appetite. Three replicate groups of fish (average weight of5.9g)were fed to visual satiety with pellet feed at different feeding frequencies (three meals a day, two meals a day, one meal a day, two meals every2days or one meal every2days). Weight gains and feed intakes of the fish fed triple a day, twice a day and twice every2days were significantly higher than those of the fish fed once a day or once every2days (P<0.05), but feed efficiency ratios in the fish fed once a day, twice every2days and once every2days were significantly higher than those of the fish fed triple a day or twice a day (P<0.05). As feeding frequency gradually decreased, moisture content of fish body increased. Feeding frequency had no significant effects on protein and fat content of fish body, except for fish fed once every2days. Hepatosomatic indices (HIS) of fish with different feeding frequencies were not significantly different and the livers were normal. It is concluded that two meals every2days is more effective than other feeding frequencies for improving growth performance of juvenile Darkbarbel catfish from5.9to31.8g. Gastric evacuation is a simple and convenient way to evaluate optimal feeding frequency of juvenile Darkbarbel catfish.