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(P0.05);GSH-Px,GST,GR in serum were not sensitive to the cadmium(P0.05),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(P0.05);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(P0.05),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.