铅、镉联合暴露对蛋鸡生产性能、蛋品质及鸡蛋中微量元素含量的影响

Effects of Combined Exposure to Lead and Cadmium on Performance,Egg Quality and Egg Trace Elements Content of Laying Hens

本研究旨在探讨铅(Pb)、镉(Cd)联合暴露对蛋鸡生产性能、蛋品质和鸡蛋中微量元素含量的影响。试验选择120只体重一致的40周龄海兰褐壳蛋鸡,随机分为4组,每组3个重复,每个重复10只鸡。对照组饮用纯净水,试验组采用饮水对蛋鸡进行Pb(100 mg/L)、Cd(50 mg/L)单独和联合(100 mg/L Pb+50 mg/L Cd)暴露,试验期8周。结果表明,1)与对照组比较,Pb组、Cd组及Pb+Cd组料蛋比、平均日采食量、平均蛋重均无显著差异(P>0.05);第8周Cd组、Pb组及Pb+Cd组产蛋率分别较对照组下降了14.73%(P<0.01)、6.21%(P<0.05)、27.50%(P<0.01)。2)与对照组比较,Pb组、Cd组及Pb+Cd组蛋壳颜色、厚度、强度及蛋形指数无显著差异(P>0.05);不同时间,哈氏单位和蛋黄色泽均不同程度低于对照组,差异显著或极显著(P<0.05或P<0.01)。3)Pb组、Cd组、Pb+Cd组不同时间鸡蛋中的铜、铁、锰、锌、硒含量显著或极显著低于对照组(P<0.05或P<0.01),且Pb+Cd组的降低幅度显著或极显著高于Pb组、Cd组(P<0.05或P<0.01)。鸡蛋中Pb、Cd的残留随暴露时间延长逐渐升高,第8周Cd组鸡蛋中Cd含量为14.920μg/kg,Pb组鸡蛋中Pb含量为97.815μg/kg,Pb+Cd组鸡蛋中Cd含量为17.007μg/kg,Pb含量为146.576μg/kg。综上所述,亚慢性Pb、Cd及其联合暴露主要引起产蛋率和蛋品质的下降,降低哈氏单位、蛋黄色泽及鸡蛋中铜、铁、锰、锌、硒含量。Pb、Cd联合暴露对蛋鸡生产性能及蛋品质影响呈叠加效应(协同效应)。

This experiment was conducted to study the effects of combined exposure lead （Pb） and cadmium （Cd） on performance, egg quality and egg trace elements content in of laying hens. A total of 120 forty-week-old Hy-line brown hens with the same body weight were randomly allocated to 4 groups with 3 replicates per group and 10 hens per replicate. Hens in the control group drank purified water, and hens in the experiment groups drank water supplemented with 100 mg/L Pb, 50 mg/L Cd and 100 mg/L Pb＋50 mg/L Cd, respectively. The experiment lasted for 8 weeks. The results showed as follows： 1） compared with the control group, there were no significant differences in average daily feed intake, average egg weight and the ratio of feed to egg in groups Pb, Cd and Pb＋Cd （P〉0.05）; the laying rate in groups Cd, Pb and Pb＋Cd was decreased by 14.73% （P0.05）; the haugh unit and yolk color in groups Pb and Cd were significantly decreased at different times （P〈0.05 or P〈0.01）. 3） The contents of Zn, Cu, Mn, Fe and Se in groups Pb and Cd were significantly lower than those in control group （P〈0.05 or P〈0.01）, and the decrease rate in group Pb＋Cd was significantly higher than that in groups Pb and Cd （P〈0.05 or P〈0.01）. The contents of Pb and Cd in eggs gradually increased with exposure time. The eggs Cd content in group Cd was 14.920 μg/kg, the eggs Pb content in group Pb was 97.815 μg/kg, and the eggs Cd and Pb contents in group Pb＋Cd were 7.007 and 146.576 μg/kg at the eighth week, respectively. In conclusion, sub-chronic exposure to Cd and/or Pb decrease the laying rate and egg quality, and reduce haugh unit, yolk color and the contents of Mn, Fe, Cu, Zn and Se in eggs. Combined exposure to Pb and Cd has superimposed effect （synergistic effect） on performance and egg quality of laying hens.