饮水添加壳聚糖对鸡白痢沙门氏菌攻毒蛋鸡蛋品质、血清抗氧化指标、肝脏损伤和输卵管炎症的缓解作用

Alleviating Effects of Supplemental Chitosan in Drinking Water on EggQuality, Serum Antioxidant Indices, Liver Injury and OviductInflammation of Laying Hens Challenged with Salmonella pullorum

本试验旨在研究饮水添加壳聚糖(CS)对鸡白痢沙门氏菌(SP)攻毒蛋鸡蛋品质、血清抗氧化指标、肝脏损伤和输卵管炎症的缓解作用。选取体重、产蛋率相近的180羽35周龄健康海兰褐蛋鸡,随机分为3组,每组5个重复,每个重复12羽。3组分别为对照组(CON组)、攻毒组(SP组)和壳聚糖组(CS组),均饲喂相同的基础饲粮。试验期7 d。试验第1天,分别于09:00和17:00各进行1次攻毒处理,其中SP组和CS组每只试验鸡均口服1 mL活菌数为1×109 CFU/mL的SP菌液,CON组每只试验鸡口服1 mL生理盐水;第2次攻毒结束后,立即在CS组饮水中添加0.4%CS,且连续7 d服用含CS的水。结果表明:1)与CON组相比,SP组产蛋率显著降低(P<0.05),血清谷草转氨酶(AST)活性以及白蛋白(ALB)和丙二醛(MDA)含量显著提高(P<0.05),血浆白细胞介素-1β(IL-1β)和SP抗体(SP-Ab)含量显著提高(P<0.05),血浆白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)含量显著降低(P<0.05);SP攻毒后第1天和第3天,SP组蛋壳强度显著降低(P<0.05)。SP组蛋鸡出现典型的白痢、嗜睡及精神不佳等临床症状,组织病理学观察到输卵管膨大部组织绒毛膜碎裂,出现多处炎性浸润灶和脂肪变性以及少量肝细胞坏死崩解和核固缩等明显的病理改变。2)与SP组相比,CS组产蛋率显著增高(P<0.05),血清AST活性以及MDA含量显著降低(P<0.05),肝脏指数、血清谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)活性以及血浆SP-Ab含量显著提高(P<0.05);饮水中添加CS后第3天和第7天,CS组蛋壳强度显著提高(P<0.05)。SP组蛋鸡临床症状有所缓解,病理学观察到输卵管膨大部和肝脏损伤均有所缓解。3)与CON组相比,CS组产蛋率无显著差异(P>0.05),肝脏指数、血清ALB和总蛋白(TP)含量、血清GSH-Px和SOD活性以及血浆SP-Ab含量显著提高(P<0.05),血浆IL-6含量显著降低(P<0.05)。综上所述,饮水中添加0.4%CS可通过减轻蛋鸡肝脏损伤和输卵管炎症、增强机体抗氧化功能以及调节免疫炎症反应等,从而缓解SP感染以及由此引起的产蛋性能和蛋品质下降。

This study was conducted to investigate the alleviating effects of supplemental chitosan(CS)in drinking water on egg quality,serum antioxidant indices,liver injury and oviduct inflammation of laying hens challenged with Salmonella pullorum(SP).A total of 180 healthy Hy-Line brown laying hens of 35-week-old with similar body weight and laying rate were randomly divided into 3 groups with 5 replicates per group and 12 hens per replicate.Hens in the three groups,control group(CON group),challenge group(SP group)and chitosan group(CS group),were fed the same basal diet.The experiment lasted for 7 days.On day 1 of the experiment,each chicken in SP group and CS group was given 1 mL SP bacterial solution with a viable bacterial count of 1×109 CFU/mL orally,and each chicken in CON group was given 1 mL normal saline orally at 09:00 and 17:00,respectively.After the second challenge,0.4%CS was supplemented to the drinking water in CS group immediately,and the CS containing water was taken for 7 consecutive days.The results showed as follows:1)compared with CON group,the laying rate in SP group was significantly decreased(P<0.05),the glutamic oxalacetic transaminase(AST)activity and contents of albumin(ALB)and malondialdehyde(MDA)in serum were significantly increased(P<0.05),the contents of interleukin-1β(IL-1β)and SP antibody(SP-Ab)in plasma were significantly increased(P<0.05),and the contents of interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in plasma were significantly decreased(P<0.05);on days 1 and 3 after SP challenge,the eggshell strength in SP group was significantly decreased(P<0.05).Typical clinical symptoms such as white dysentery,lethargy and poor mental state of laying hens were observed in SP group.Histopathological observations showed significant pathological changes such as fragmented chorionic membrane in the oviduct magnum tissues,multiple inflammatory infiltrative lesions and steatosis,as well as a small amount of hepatocyte necrosis,disintegration and nuclear pyknosis.2)Compared with SP group,the laying rate in CS group was significantly increased(P<0.05),the AST activity and MDA content in serum were significantly decreased(P<0.05),the liver index and activities of glutathione peroxidase(GSH-Px)and superoxide dismutase(SOD)in serum as well as the SP-Ab content in plasma were significantly increased(P<0.05);on days 3 and 7 after supplementing CS to drinking water,the eggshell strength in CS group was significantly increased(P<0.05).The clinical symptoms of laying hens in SP group were alleviated,and pathological observations showed that the damage to oviduct magnum and liver was alleviated.3)Compared with CON group,the laying rate in CS group had no significant difference(P>0.05),the liver index,contents of ALB and total protein(TP)in serum,activities of GSH-Px and SOD in serum and SP-Ab content in plasma were significantly increased(P<0.05),and the IL-6 content in plasma was significantly decreased(P<0.05).In conclusion,the supplementation of 0.4%CS in drinking water can alleviate SP infection and the resulting decline in laying performance and egg quality by reducing liver injury and oviduct inflammation,enhancing antioxidant function and regulating immune inflammatory response of laying hens.