丙氨酰—谷氨酰胺投喂方式对建鲤生长和抗急性拥挤胁迫能力的影响

以初始体质量为(33.52±0.17)g建鲤为研究对象,在室内单循环养殖系统中进行8周(w)生长试验,分别配制成添加0.0%(对照)和0.5%(试验)丙氨酰—谷氨酰胺(Ala-Gln)的等氮等能(35%CP、17 kJ/g)饲料,采用5种投喂方式:连续8 w投喂对照饲料(Ⅰ);试验饲料2 w间隔投喂(Ⅱ);前4 w投喂试验饲料,后4 w投喂对照饲料的间隔投喂(Ⅲ);前4 w投喂对照饲料,后4 w投喂试验饲料的间隔投喂(Ⅳ);8 w连续投喂试验饲料(Ⅴ)。养殖试验结束时,进行急性拥挤胁迫试验。探讨Ala-Gln投喂方式对建鲤生长和抗急性拥挤胁迫能力的影响。结果表明,Ala-Gln连续投喂和间隔投喂组的生长都显著高于对照组(P<0.05)。2 w间隔投喂的特定生长率都显著高于4 w间隔和连续8 w投喂的饲料组(P<0.05);前4 w间隔投喂组的特定生长率要显著高于8 w连续投喂组(P<0.05)。血清皮质醇和血糖分别在急性胁迫后恢复0和1 h时达到高峰,血清HSP70在胁迫后恢复1～12 h都保持较高水平,然后下降,胁迫后恢复48 h达到胁迫前的水平。各种投喂方式组的血糖和血清皮质醇含量都显著低于对照组(P<0.05)。胁迫后恢复期,血糖迅速升高幅度最小的是2 w间隔投喂组,最先恢复到胁迫前状态的是2 w间隔投喂组和前4 w投喂的4 w间隔投喂组。胁迫后恢复期,各投喂组的血清HSP70都显著高于对照组(P<0.05),胁迫后恢复48和72 h时,后4 w投喂的4 w间隔投喂组和连续8 w的投喂组的血清HSP70显著高于对照组(P<0.05)。

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

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(P<0.05).Specific growth rate of Ⅱ was higher than that of Ⅲ,Ⅳ,Ⅴ groups(P<0.05)and that of Ⅲ was higher than that of Ⅴ group(P<0.05).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(P<0.05).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(P<0.05),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(P<0.05).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.