Effects Of Lonicera Flos And Cnicus Japonicus Compound Extract On Intestinal And Oviduct Health Of Laying Hens During The Late Laying Period And Related Mechanisms

The aim of this study was to investigate the effects of Lonicera flos and Cnicus japonicus compound extracts（LCE）with chlorogenic acid and flavonoids as main active ingredients on intestinal and oviduct health of laying hens during the late laying period.In the experiment,1 728 73-week-old Roman Pink laying hens were randomly assigned into 4 groups with 18 replicates and 24 layers in each replicate,control group fed basal diet,the treatment groups were fed basal diets supplemented with 300,500,1 000 mg/kg LCE,respectively.The pre-trial period was 2 weeks and the trial period was 9 weeks.Ten hens from each group was selected and slaughtered for sampling at weeks 78 and 83.The results showed that:1.Effects of LCE on production performance and egg quality of laying hens during the late laying periodCompared with the control group,300 mg/kg LCE significantly increased yolk color at week 78（P<0.05）;500 mg/kg LCE significantly improved Haugh unit at week 83（P<0.05）;1 000 mg/kg LCE significantly increased yolk color,egg shell thickness at week 78 and albumen height,Haugh unit at week 83（P<0.05）;LCE addition significantly increased egg shell thickness at week 83（P<0.05）.2.Effects of LCE on blood biochemical indices,organ indices and follicular development of laying hens during the late laying periodCompared with the the control group,300 mg/kg LCE significantly increased plasma glutathione peroxidase（GSH-Px）activity and decreased plasma hydrogen peroxide（H₂O₂）content at week 83（P<0.05）;500,1 000 mg/kg LCE significantly increased serum luteotropic hormone（LH）level at week 83（P<0.05）,significantly decreased plasma H₂O₂ levels at weeks 83 and 78,respectively（P<0.05）;LCE supplementation significantly increased plasma GSH-Px activity at week 78（P<0.05）.3.Effects of LCE on the intestinal health of laying hens during the late laying periodCompared with the control group,300 mg/kg LCE significantly increased ileal villus height,the ratio of villus height to crypt depth（V/C）at week 78 and duodenal villus height,jejunal V/C and catalase from micrococcus lysodeiktic（CAT）activity at week 83（P<0.05）,significantly reduced malondialdehyde（MDA）content in the jejunum at week 78 and H₂O₂,MDA levels in the jejunum at week 83（P<0.05）;500mg/kg LCE significantly up-regulated the m RNA expression of occludin,mucin-2,CAT,ERK in the jejunum at week 78（P<0.05）,significantly increased duodenal villus height,ileal villus height,ileal V/C,jejunal CAT activity,cecal Lactobacillus population at week 83（P<0.05）,significantly reduced jejunal MDA content,relative m RNA expression of jejunal i NOS at week 78 and serum endotoxin content,jejunal H₂O₂and MDA content at week 83（P<0.05）;1 000 mg/kg LCE significantly improved ileal villus height,ileal V/C and up-regulated the m RNA expression of occludin,mucin-2,E-cadherin,HO-1,ERK in the jejunum at week 78（P<0.05）,significantly improved duodenal villus height,ileal villus height,ileal V/C,jejunum CAT activity at week 83 and up-regulated the m RNA expression of SOD,Nrf2,ERK in the jejunum at week 83（P<0.05）,significantly reduced MDA content in the jejunum at week 78 and serum endotoxin content,jejunal H₂O₂content,jejunal MDA content at week 83（P<0.05）.4.Effects of LCE on oviduct health of laying hens during the late laying periodCompared with the control group,300 mg/kg LCE significantly down-regulated the m RNA expression of IL-1β,TNF-αin the magnum at week 83（P<0.05）;500mg/kg LCE extract significantly up-regulated OVAY in the magnum at week 78（P<0.05）,significantly down-regulated the m RNA expression of IFN-γ,IL-1β,TNF-αand H₂O₂ content in the magnum at week 83（P<0.05）;1 000 mg/kg LCE significantly reduced magnum H₂O₂ content at week 78（P<0.05）,significantly down-regulated the m RNA expression of IFN-γ,IL-1β,TNF-αand H₂O₂ content in the magnum at week 83（P<0.05）.Compared with the control group,300 mg/kg LCE significantly increased isthmus CAT,GSH-Px activities at week 78 and isthmus CAT activity at week 83（P<0.05）,significantly down-regulated the m RNA expression of i NOS in the isthmus at week 78 and isthmus H₂O₂ content at week 83（P<0.05）;500 mg/kg LCE significantly increased isthmus GSH-Px activity at week 78 and isthmus CAT,GSH-Px activities at week 83（P<0.05）,significantly down-regulated the m RNA expression of i NOS in the isthmus at week 78 and isthmus H₂O₂ content at week 83（P<0.05）;1 000 mg/kg LCE significantly increased isthmus GSH-Px activity at week78 and isthmus CAT activity,the m RNA expression of TXN in the isthmus at week 83（P<0.05）,significantly down-regulated the m RNA expression of i NOS in the isthmus at week 78 and isthmus H₂O₂ content at week 83（P<0.05）.Compared with the control group,300 mg/kg LCE significantly increased uterus total superoxide dismutase（T-SOD）activity and up-regulated the m RNA expression of Ca²⁺-ATPase in the uterus at week 83（P<0.05）,significantly down-regulated the m RNA expression of TNF-αin the uterus at week 83（P<0.05）;500 mg/kg LCE significantly up-regulated the m RNA expression of OC-116,ALP,CA in the uterus at week 78（P<0.05）,significantly reduced uterus MDA content and the m RNA expression of TNF-αin the uterus at week 83（P<0.05）;1 000 mg/kg LCE significantly up-regulated the m RNA expression of OVA,Ca²⁺-ATPase,OC-116,ALP,CA in the uterus at week 78（P<0.05）,significantly reduced uterus MDA content and the m RNA expression of TNF-αin the uterus at week 83（P<0.05）.In conclusion,the addition of LCE could improve the intestinal morphology of laying hens in the late stage of egg production,improve intestinal function by reducing the level of serum endotoxin and regulating the expression of barrier genes,and enhance the body’s antioxidant capacity by regulating the ERK gene to activate the Keap1/Nrf2 signaling pathway.The addition of 500 or 1 000 mg/kg LCE to diet could enhance the antioxidant capacity of the oviduct,downregulate the expression of inflammatory cytokines in the oviduct in laying hens in the late stage of egg production,alleviate oviduct inflammation,and regulate the expression of oviduct function genes,thus improving egg quality.