| The experiment was conducted to investigate the effects of Astragalus Membranaceus and Astragalus polysaccharides on laying performance, egg qualities, antioxidant status and immune function of laying hens. 945 Hy-Line brown laying hens at 27 wk of age were randomly allocated into 7 treatments with 5 replicates, and each replicate contained 27 hens. The seven dietary treatments included a control that was a corn-soybean meal basal diet, basal diet supplemented with 5, 10 or 15 g/kg diet of Astragalus Membranaceus root powder and 100, 200 or 300 mg/kg Astragalus polysaccharides respectively (denoted as Control, AMP5, AMP10, AMP15, APS100, APS200 and APS300). The experiment comprised of a week of adaptation and 10 weeks of measurement period. ADFI, laying rate, average egg weight, egg mass and feed conversion were calculated each week and egg qualities, antioxidant status, serum antibody titer and blood index were determined on d 35 and d 70.The result of this experiment indicated: there was no significant difference in ADFI, laying rate, average egg weight, feed conversion, eggshell thickness, egg index, egg yolk weight and eggyolk color among treatments (P>0.05). However, laying hens of AMP5 and AMP10 had higher (P<0.05) egg mass during the second 5-wk and the entire period and laying hens of APS300 had higher egg albumen weight (P<0.05) at d 70 than that of control birds. Supplementation of AMP and APS significantly increased (P<0.05) the activities of TSOD, T-AOC, and GSH-Px in serum and eggyolk TSOD, but reduced (P<0.05) the concentrations of serum and eggyolk MDA, and eggyolk cholesterol.At d 35, Laying hens consuming diet AMP10 had the highest (P<0.05) activities of serum GSH-Px, but lowest (P<0.05) serum MDA concentration compared to Control and other AMP groups. Laying hens of AMP10 and APS15 had lower (P<0.05) eggyolk cholesterol than that of control birds. Laying hens consuming diet APS100 and APS200 had higher (P<0.05) granulocyte and consuming diet AMP10 and APS300 had higher (P<0.05) Newcastle disease than laying hens consuming diet Control and AMP5, whereas difference for Avian influenza H5Re-5 antibody titer was only observed between Control and AMP5 (P<0.05). At d 70, supplementation of AMP and APS both increased (P<0.05) the activities of serum T-AOC but reduced (P<0.05) the concentrations of serum and eggyolk MDA, and eggyolk cholesterol. Laying hens consuming diet AMP5 and AMP10 had higher (P<0.05) activities of serum T-AOC and TSOD than laying hens consuming diet Control and AMP15. Laying hens consuming diet AMP10 had higher (P<0.05) intermediate cells but lowest concentrations of serum MDA compared to Control and other AMP groups. Laying hens in APS200 had higher (P<0.05) granulocyte, intermediate cells and Avian influenza H9 antibody titer as compared to Control.As the levels of AMP increasing from 0 to 15 g/kg diet and APS increasing from 0 to 300 mg/kg diet, activities of serum T-AOC were linearly and/or quadratically increased (P<0.05) but serum and eggyolk MDA, and eggyolk cholesterol were linearly and/or quadratically decreased at d 35 and d 70 of the experiment. There were no differences in eggyolk cholesterol and MDA concentrations at d 35 and d 70 and eggyolk TSOD between AMP groups and APS groups (P>0.05). Activities of serum GSH-Px at d 35 and serum TAOC at d 70 in AMP groups were higher than that in APS groups (P<0.05), whereas activities of eggyolk TSOD at d 35 in APS groups were higher than that in AMP groups (P<0.05).It was concluded that the supplementation of Astragalus Membranaceus and Astragalus polysaccharides could increase the birds'laying performance, immunity property, antioxidant status and decrease eggyolk cholesterol of laying hens. And the optimal levels used in laying hens were 1.0 % and 200 mg/kg respectively. Effects of AMP groups were prior to APS groups in improving antioxidant status of laying hens.
|
PDF Full Text Request