饲料中镉含量对蛋鸡生产性能及抗氧化功能的影响

为研究日粮中低剂量镉对蛋鸡生产性能和血清、肝肾抗氧化能力的影响,将192羽巴布考克B300蛋鸡随机分为4组,每组3个重复。对照组饲喂玉米-豆粕型基础日粮,试验组日粮为在基础日粮中分别添加5、10、20 mg/kg的镉(氯化镉形式,CdCl2.2.5H2O),试验期9周。结果表明:在1～3、4～6、7～9周,试验组的产蛋率、日采食量均低于对照组(P>0.05);各组在第7～9周时的采食量显著低于1～3周(P<0.05);血清中GSH-Px、GST、GR酶活力对镉不敏感(P>0.05),随镉添加量升高肝肾中GSH-Px活力先升后降,试验组肝肾中总巯基含量较对照组有显著升高(P<0.05);血清和肝肾中总SOD、CuZn-SOD、CAT活力随镉添加量升高呈先升后降的趋势;血清和肝肾中MDA、NO含量随着镉添加量的升高显著升高(P<0.05),总抗氧化能力均呈下降趋势。试验结果证实,镉可引起产蛋鸡体内抗氧化功能受损,机体产生氧化应激,并可能由此导致蛋鸡的生产性能下降。

Effects of Dietary Cadmium on Production Performance and Antioxidant Capacity of Laying Hens

This experiment was conduct to investigate the effects of low-levels of dietary cadmium on production performance and antioxidative parameters in serum,liver and kidney of laying hens.One hundred and ninety two 40-w-old Babcock B-300 laying hens were randomly divided into four groups with three replicates per group and 16 laying hens per replicate.The diet of control group was a basal corn-soybean meal diet.The experimental diet was supplemented with cadmium(CdCl2·2.5H2O) 5 mg/kg,10 mg/kg and 20 mg/kg into basal diet,respectively.The experiment lasted for 9 weeks.The results showed that in 1~3,4~6 and 7~9 week,the laying rate,ADFI of three trail group were lower than those of control group;in 7~9 week,the ADFI of all groups were lower than that in 1~3 week(P<0.05);GSH-Px,GST,GR in serum were not sensitive to the cadmium(P>0.05),GSH-Px activity in liver and kidney first increased and then decreased with the added level of cadmium increased;sulfhydryl levels of trail group in liver and kidney were higher than those of control group(P<0.05);the activity of total SOD,CuZn-SOD and CAT in serum,liver and kidney declines from 5 mg/kg,10 mg/kg and 20 mg/kg group;the content of MDA and NO were significantly increased with the cadmium-added level increased(P<0.05),while T-AOC significantly decreased.These results indicated that cadmium could cause injury of body antioxidation system and induce oxidant stress of laying hens,consequently lead to a decrease of production performance of laying hens.