Effects Of Macleaya Cordata Extract On Growth Performance,Immune Performance And Intestinal Microflora Of Laying Hens

The aim of this study was to investigate the effects of Macleaya cordata extract on the performance,antioxidant activity and immune function of laying hens(0-17 WK).In this experiment,1600 female Hailan Brown chickens(160 surplus)were selected,According to 2(Macleaya plus or not)×2(chlortetracycline plus or not),the chickens were randomly divided into 4 treatments with 12 replicates in each treatment and 30 chickens in each replicate.There were two levels of Macleaya extract,Macleaya extract without adding vs.adding(Macleaya extract 500 mg/kg);each Macleaya extract was treated with two antibiotics(chlortetracycline premix: 0 vs.50 mg/kg).The experimental chickens were raised in cages.They were fed the basic diet for 1-7 days,the experimental materials of their brooding period were fed from 8days,and the experimental materials of early and late breeding period were fed from 7 weeks and 13 weeks,respectively.At the end of 6 wk,12 wk and 17 wk,slaughtering test was conducted to determine slaughter performance,organ index,tibia quality and intestinal score;liver was collected to determine liver antioxidant;blood was collected to determine serum antioxidant,cytokine and immune antibody titer.At the end of the experiment,cecal chyme was taken for 16 s high-throughput sequencing to determine the cecal microflora.The results show that:Production performance and slaughter performance : Dietary chlortetracycline supplementation had no significant effect on production performance(P > 0.05),but had the trend of increasing half eviscerated rate at 12 wk(P = 0.085)and decreasing full eviscerated rate at 17 wk(P = 0.081).The average daily gain(ADG),average body weight(BW)of 6 wk,12 wk and 17 wk laying hens were significantly increased(P < 0.05)by adding Macleaya cordata extract in the diet during the brooding period(0-6 wk)and the whole experiment period(0-17 wk),while the standard deviation(SD)of 12 wk(P = 0.080),coefficient of variation(CV)of 12 wk(P = 0.090)and coefficient of variation(CV)of 17 wk(P = 0.099)were decreased(P > 0.05).The interaction effect of aureomycin and broodin extract on the ratio of material weight in the whole experiment period was observed(P < 0.05).Compared with the control group(without aureomycin and Macleaya extract),the addition of Macleaya extract significantly reduced the feed to weight ratio in the whole experiment period(P <0.05).Antioxidant and immune properties : Dietary chlortetracycline supplementation significantly increased thymus index and bursa index(P < 0.01),increased GSH activity(P =0.084)and interleukin-6(P = 0.089)at 6 wk,and significantly decreased MDA content in serum and liver and IFN-γ level at 6 wk(P < 0.05).Dietary supplementation of Macleaya cordata extract significantly increased serum GSH-Px activity,6 wk serum T-SOD activity(P< 0.05),6 wk and 12 wk liver GSH-Px activity,12 wk and 17 wk liver T-SOD activity,6 wk bursa index and 12 wk thymus index,12 wk IFN-γ and IL-6 levels,17 wk IL-12 levels and 12 wk thymus index The antibody titers of avian influenza H9 and Newcastle disease in wk increased 6 wk IL-6(P = 0.063)and 6 wk avian influenza H9(P = 0.062),significantly decreased the serum MDA content and liver MDA content in 6 wk and 12 wk,and decreased the serum MDA content in 17 wk(P = 0.054).Chlortetracycline and Macleaya cordata extract had interaction effects on serum GSH-Px activity at 6 wk,bursal index at 6 wk and interleukin-6 level at 12 wk(P < 0.05).Compared with the group without chlortetracycline and Macleaya extract,the other three groups(chlortetracycline group,Macleaya extract group,combined with chlortetracycline and Macleaya extract group)significantly increased serum GSH-Px activity at 6 wk,bursal index at 6 wk and interleukin-6 level at 12 wk(P < 0.05),and there was no significant difference among the three groups(P > 0.05).Tibial quality and intestinal : Dietary aureomycin supplementation significantly increased tibial strength at 6 wk(P < 0.01),significantly decreased ash content at 6 wk(P <0.01),and decreased tibial strength at 12 wk(P = 0.057)and ileal score at 17 wk(P =0.057).Dietary supplementation of Macleaya cordata extract significantly increased tibial strength at 6 wk and 17 wk,significantly decreased the comprehensive score of small intestine at 6 wk(P < 0.05),and tended to decrease the ileum score at 17 wk(P =0.057).Chlortetracycline and Macleaya extract had an interactive effect on the tibial strength at 6 wk(P < 0.05).Compared with the combination of chlortetracycline and Macleaya extract group,the addition of chlortetracycline and Macleaya extract alone significantly increased the tibial strength at 6 wk(P < 0.05),and there was no difference between the two groups(P >0.05).Cecal microflora:The addition of Macleaya cordata extract in diet could significantly improve the microbial richness and diversity of cecal chyme(P < 0.05),regulate the intestinal microflora of layers,and form a unique intestinal microflora structure.Compared with the control group,Macleaya extract group increased the relative abundance of posterior wall phylum(P < 0.05),increased the relative abundance of Proteus phylum(P = 0.075),and decreased the relative abundance of Bacteroides phylum(P < 0.05).Chlortetracycline and Macleaya extract had an interactive effect on the relative abundance of bacteroideae,liyanbacteriaceae and prevotellaceae(P < 0.05).Compared with the combination of chlortetracycline and Macleaya cordata extract,the relative abundance of bacteroideae was significantly increased by Macleaya cordata extract alone(P < 0.05);compared with the control group,the relative abundance of physical research bacteroideae was decreased by Macleaya cordata extract and chlortetracycline(P < 0.05),and there was no significant difference between the two groups(P > 0.05),while the relative abundance of prevotellaceae was increased by chlortetracycline(P < 0.05)。In conclusion,Macleaya cordata extract can replace antibiotics to improve the production performance,antioxidant performance and immune performance of layers,improve tibia strength,reduce intestinal score,and promote the proliferation of intestinal beneficial bacteria.The combination of chlortetracycline and Macleaya extract had no additive effect on the function improvement.