饲料中添加红景天对吉富罗非鱼耐低温特性的影响

实验采用高山红景天(Rhodiola sachalinensis)作为饲料添加剂,探究其对低温胁迫下的吉富罗非鱼(Oreochromis niloticus,GIFT)的影响。将0.1%、0.2%、0.4%的高山红景天水煎剂粗提干粉分别添加到基础饲料(对照组),用4种实验饲料投喂吉富罗非鱼54 d,然后进行低温胁迫处理并于30、25、20、15和10℃时分别取样。结果显示:水温为10℃时,添加组的成活率为100%,显著高于对照组,添加组血清中的血糖、高密度脂蛋白胆固醇、一氧化氮浓度和肝脏中的丙二醛水平较对照组显著降低;肝脏中的超氧化物歧化酶和谷胱甘肽过氧化物酶的酶活性水平较对照组显著升高,并且添加水平越高,效果越明显。以上结果说明,饲料中添加0.1%的高山红景天粗提干粉即能对提高罗非鱼的抗低温能力起到一定的积极作用,添加0.2%和0.4%的效果更好。

Effects of Rhodiola sachaliensis on improving low-temperature tolerance characteristics of Tilapia (Oreochromis niloticus)

An experiment was conducted to study the effect of Rhodiola sachaliensis aqueous extract powder on the tilapia under low-temperature. The fishes were divided into four groups: no additives group( control group, NC) , R. sachaliensis low dose group(0. 1%), R. sachaliensis mid dose group (0. 2%) and R. sachaliensis high dose group (0. 4%). And the fishes were fed at 30 ℃ for 2 weeks followed by the experimental temperature dropped from 30 ℃ to 10 ℃ with the rate of 0. 5 ℃/d. The survival rate, blood biochemical indexes and antioxidant indexes of the fishes in four groups were deter-mined at 30 ℃, 25 ℃, 20 ℃, 15 ℃ and 10 ℃. The results showed that the survival rates of the all adding R. sachaliensis groups were significantly higher than that of the control group. At 10 ℃, compared with the control group, high density lipoprotein-cholesterol, glucose, nitric oxide, malonaldehyde content of fishes in R. sachaliensis supplement groups were significantly reduced, meanwhile superoxide dismutase levels and glutathione peroxidase activities in liver of fi-shes were significantly increased with the increasing R. sachaliensis level. In conclusion, R. sachaliensis can play a positive role in resisting low temperature in tilapia.