Effect of feeding modes of Ala-Gln on growth and resistance to crowding stress of Cyprinus carpio var. jian

Abstract

The trial was carried out on healthy Cyprinus carpio var.jian with the initial weight(33.52±0.17) g in a single recirculating system for 8 weeks.Diet was administered at concentrations 0.0%(control diet)and 0.5%(trial diet)Ala-Gln of dietary dry matter,which were fed to the C.carpio var.jian in five different feeding modes.continuously fed by control diet during eight weeks(Ⅰ,control group),trail diet at an interval of two weeks(Ⅱ),trail diet before four weeks at an interval of four weeks(Ⅲ),trail diet after four weeks at an interval of four weeks(Ⅳ),and continuously fed by trail diet during eight weeks(Ⅴ).Acute crowding stress was implemented at the last of experiment.The trail was conducted to investigate the effects of feeding modes of Ala-Gln on growth and the resisence to acute crowding stress for C.carpio var.jian.Results indicated that growth of different feeding modes of Ala-Gln was significantly higher than that of control group(P0.05).Specific growth rate of Ⅱ was higher than that of Ⅲ,Ⅳ,Ⅴ groups(P0.05)and that of Ⅲ was higher than that of Ⅴ group(P0.05).After acute crowding stress,Serum cortisol reached peak at 0 h and glucose at 1h,serum HSP70 remained high level before 1-12 h then declined,at last,restored the normal level until 48 h.Serum cortisol and glucose were lower in every feeding mode than in control group(P0.05).The smallest increase of serum glucose was Ⅱ group,The first recovery occurred in Ⅱ and Ⅲ group after stress.Serum HSP70 in every feeding mode was significantly higher than that in the control group(P0.05),and returned to normal state in 48 h and 72 h.Serum HSP70 in Ⅳ and Ⅴ groups was still significantly higher than the control(P0.05).In the current experiment,it concluded that adding Ala-Gln could improve the growth and resistance to crowding stress of C.carpio var.jian.There were significant differences of every feeding mode.Given economic efficiency and practicability,interval feeding modes will be suggested in the practical culture of C.carpio var.jian.