Effects Of The Diet Supplemented With Organic Chromium On Production Performance,Egg Qualities And Serum Biochemical Traits Of Laying Hens

In order to discover the mechanism of organic chromium and use it effectively , Two experiments were conducted to investigate the effect of organic chromium on egg production performance, egg quality, serum biochemical traits and immune responses of normal layers and heat stressed layers. Experiment Ⅰ. A total of 480 25—week old Roman commercial layers were randomly allotted to one of five treatments according to a 2*2 factorial arrangement ,and fed a basal corn-soybean meal diet(control) and the basal diets supplemented with 2.0 or 4.0 mg/kg chromium either as yeast or picolinate respectively under normal temperature. The experiment last 60 days to study the effect of organic chromium on egg production performance and egg quality on normal temperature. Experiment Ⅱ . The same 480 91—week old Roman commercial were used to study the effect of organic chromium on egg production performance, egg quality, serum biochemical traits and immune responses, the diets and the experimental design were the same with ExperimentⅠ.The result showed :Both picolinate chromium and chromium yeast chromium can improve the production performance to some extent on normal temperature and heat stress. The laying rates of the layers fed the diets supplemented with 0.2mg/kg and 0.4mg/kg Cr were increased by 1.31%和2.67%. The average egg weight of the layers fed the diets supplemented with 0.2mg/kg and 0.4mg/kg Cr were increased by 1.31%和2.67%. The organic chromium can improve the production performance more quickly on normal temperature and reduce the negative effect of heat stress more obvious. Layers fed the diets supplemented with 0.2mg/kg and 0.4mg/kg Cr had higher yolk color than those fed the control diet(p<0.01). When wheat is used for energy feed on laying eggs,the yolk color will be decreased.,The diet fed with organic chromium can increase the yolk color and improve its commercial value.Cr level influenced the serum uric(p<0.01),Layers fed the diets supplemented with 0.4mg/kg Cr had lower serum uric than those fed the control diet and 0.4mg/kg Cr. It indicate organic chromium can prevent the process of protein conversation caused by heat stress.There were no differences in reducing the negative effects of heat stress and improving the quality of eggs between yeast chromium and picolinate chromium..