The effects of dietary vitamin C sources and levels on growth in juvenile sea cucumber(Apostichopus japonicus)
WANG Ji-qiao1,SU Jiu-wang1,JIANG Yu-sheng1,ZHANG Jian-cheng2,LIANG Zhi-jun3(1.Life Science and Technology Institute,Dalian Fisheries University,Dalian 116023,China;2.Dalian Pacific Seafood Co.,LtD,Dalian 116045,China;3.Liaoning Bureau of Fishery Port Supervision,Dalian 116000,China)
Few studies have been reported on effects of dietary vitamin C sources and levels on growth of juvenile sea cucumber(Apostichopus japonicus),though vitamin C as an essential micronutrition for animals is widely added to feed in fish and shrimp.The sea cucumber juveniles averaging 2.29 g in body weight were randomly stocked into 39 plastic tanks of each 45 cm×31 cm×30 cm at rate of 15 individuals per tank and fed formulated feed containing 7.63% crude protein(corn gluten as only protein source) and 3.89% crude fat supplemented with 5 levels(0 mg/kg,500 mg/kg,1 000 mg/kg,2 000 mg/kg and 4 000 mg/kg diet) of L-ascorby1-2-polyphosphate(LAPP),L-ascorby1 palmitate(LAP) or L-ascorby1-2-monophosphate-magnesium(APM) to investigate the effects of dietary vitamin C sources and levels on the growth of the juveniles with triplication at water temperatures of 11.0~14.0℃ for 90 days.The higher specific growth rate(SGR),protein efficiency ratio(PER),and lower feed conversion ratio(FCR) were found in the juveniles fed the diets supplemented with the vitamin C than those in the juveniles in the control groups(P0.05).The juveniles fed the diets supplemented with LAPP(0.21(%/d)) had the maxima1 SGR(0.21(%/d)),followed by the juveniles(0.17(%/d)) fed the diets supplemented with LAP and the next in the juveniles(0.15(%/d)) fed the diets supplemented with APM,75.00%,41.67% and 25.00% higher than those in the control groups.There were the maximal PER in the juveniles fed the diets supplemented with LAPP(12.57%),followed by the juveniles fed the diets supplemented with LAP(7.76%) and the next in the juveniles fed the diets supplemented with APM(6.86%),127.72%,40.58% and 24.28% higher than those in the control groups(5.52%).The FCR was in a descendent order arranged for the vitamin C's as follows: LAPPLAPAPM.Second-degree polynomial regression revealed that the maximal apparent digestibility of dietary protein,SGR and minimal FCR were observed in the juveniles fed the diets supplemented with LAPP at a rate of 2 000~2 500 mg/kg,APM 1 000~1 500 mg/kg and LAP 2 000~3 125 mg/kg.The results come to the conclusion from the improvement of growth in the sea cucumber that the optimal dietary vitamin C micronutrition is of LAPP.
【CateGory Index】： S968.9
【CateGory Index】： S968.9