饲料β-胡萝卜素水平对镇海林蛙蝌蚪生长发育的影响

为探讨饲料中添加不同剂量的β-胡萝卜素对于镇海林蛙(Rana zhenhaiensis)蝌蚪生长、幼蛙形态和运动表现及肝脏酶活的影响。将镇海林蛙蝌蚪(Gosner 25~26)288尾随机分为4个处理组。各组分别添加0、50、500和1200 mg/kgβ-胡萝卜素,直至镇海林蛙蝌蚪变态发育完全。结果显示:(1)不同处理组间蝌蚪发育中期的体重、体长和尾长组间差异不显著,而蝌蚪中期发育的历期在组间差异显著,对照组中期发育的历期显著快于β-胡萝卜素处理组。(2)不同处理组间蝌蚪的增重率、特定生长率和变态率差异不显著,对照组的变态时间显著短于β-胡萝卜素处理组,β-胡萝卜素处理组则随着浓度的增加而变态时间缩短。(3)不同处理组间幼蛙体长、头长、前臂及手长和后肢长差异显著,但幼蛙体重差异不显著。(4)不同处理组间幼蛙平均跳跃距离差异显著,50和500 mg/kgβ-胡萝卜素处理组幼蛙平均跳跃距离显著大于另外两组。(5)幼蛙的过氧化氢酶(CAT)活力在不同处理组间差异显著,50 mg/kgβ-胡萝卜素组的酶活显著大于其它处理组,但是幼蛙肝脏总超氧化物歧化酶(T-SOD)活力差异不显著。综上所述,饲料中添加500 mg/kgβ-胡萝卜素试验组,可以显著减缓镇海林蛙蝌蚪的早期发育,延长变态时间,形成较大的幼蛙个体,积累能量较多,运动性能显著增强,个体的适合度增加。

Effects of feed β-carotene levels on the growth performance of Rana zhenhaiensis tadpoles

This experiment was conducted to evaluate the effect of different doses dietaryβ-carotene supplementation on growth performance,motor function and liver enzyme activity for Rana zhenhaiensis tadpoles.A total of 288 tadpoles(Gosner 25-26)were randomly allocated to 4 groups with 3 replicates per group and 24 tails per replicate.Tadpoles were fed the basic diet supplemented with 0,50,500 and 1200 mg/kgβ-carotene,respectively.The experiment ended when R.zhenhaiensis tadpoles complete metamorphosis.The results showed that the body weight,snout-vent length and tail length of tadpoles between each groups had no significant difference.However,a significant difference was found in the Gosner that the control group significantly grow faster than that in theβ-carotene groups.The weight gain rate,specific growth rate and metamorphosis rate between each groups had no significant difference,The metamorphosis time of the control group was significantly shorter than theβ-carotene treatment groups.The metamorphosis time shortened with the increase ofβ-carotene concentration.Snout-vent length,head length,length of lower arm and hand and hindlimb length of the froglets between the experimental groups were significantly different with the control group(P<0.01),the control group indexes were smaller than other groups,However,the weight had no significant difference between each groups.The average jumping distance of froglets between the groups was significantly different,the 50 and 500mg/kgβ-carotene groups were significantly greater than the 1200 mg/kgβ-carotene and the control group.Catalase(CAT)activity of froglets liver had a significant difference,and 50 mg/kgβ-carotene group was significantly higher than other treatment groups.However,total superoxide dismutase(T-SOD)activity of froglets liver had no significant difference.In conclusion,500 mg/kgβ-carotene in the feed can significantly slow down the early development of R.zhenhaiensis tadpole,prolong the metamorphosis time,form larger froglets,significantly enhance the accumulation of energy,the motor performance of froglets,and the fitness of froglets.