研究论文

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

  • 彭金虎 , 1, 2 ,
  • 林静 1 ,
  • 邱凯 1 ,
  • 王晶 1 ,
  • 张海军 1 ,
  • 武书庚 , 1, * ,
  • 李茜 , 3, * ,
  • 王晓丹 2
展开
  • 1 中国农业科学院饲料研究所,北京 100081
  • 2 河北农业大学中兽医学院,保定 071000
  • 3 河北省畜牧兽医研究所,保定 071000
* 武书庚,研究员,博士生导师,E-mail: ;
李茜,研究员,硕士生导师,E-mail:

彭金虎(1998—),男,河北邯郸人,硕士研究生,从事家禽健康研究。E-mail:

Copy editor: 田艳明

收稿日期: 2023-07-26

  网络出版日期: 2024-01-12

基金资助

国家重点研发计划(2022YFC2105005)

现代农业产业技术体系(CARS-40-S03)

中国农业科学院农业科技创新工程(ASTIP)

Alleviating Effects of Supplemental Chitosan in Drinking Water on Egg Quality, Serum Antioxidant Indices, Liver Injury and Oviduct Inflammation of Laying Hens Challenged with Salmonella pullorum

  • PENG Jinhu , 1, 2 ,
  • LIN Jing 1 ,
  • QIU Kai 1 ,
  • WANG Jing 1 ,
  • ZHANG Haijun 1 ,
  • WU Shugeng , 1, * ,
  • LI Qian , 3, * ,
  • WANG Xiaodan 2
Expand
  • 1 Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
  • 2 College of Traditional Chinese Veterinary Medicine, Hebei Agricultural University, Baoding 071000, China
  • 3 Hebei Provincial Institute of Animal Husbandry and Veterinary Medicine, Baoding 071000, China
* WU Shugeng, professor, E-mail: ;
LI Qian, professor, E-mail:

Received date: 2023-07-26

  Online published: 2024-01-12

摘要

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。

本文引用格式

彭金虎 , 林静 , 邱凯 , 王晶 , 张海军 , 武书庚 , 李茜 , 王晓丹 . 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[J]. 动物营养学报, 2024 , 36(1) : 267 -278 . DOI: 10.12418/CJAN2024.025

Abstract

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.

鸡白痢是鸡白痢沙门氏菌(Salmonella pullorum,SP)感染引起的一种败血性疾病,传染性强,常通过带菌母鸡以蛋为媒介传给下一代,成年鸡感染以生殖器病变为特征,伴着肝脏、肠道及脾脏炎症[1],长期带菌会影响病鸡生产性能,甚至造成死亡[2],给家禽养殖业带来巨大经济损失[3]。近年来,SP耐药性呈增强趋势[4],抗生素治疗已然失去优势;我国实施的“饲料禁抗、养殖减抗和产品无抗”政策,进一步促进了替抗产品的研发。壳聚糖(chitosan,CS)是一种带正电荷的碱性阳离子多糖[5],具有抗炎、抗氧化[6]、抑菌[7]及降血脂[8]等作用。CS因其优良的生物降解性、生物相容性、吸附性及无毒等特性,被广泛用于食品保鲜、农业、制药、临床治疗及环保等领域[9]。研究表明,饲粮添加300 mg/kg CS可有效缓解仔猪肠道炎症,促进仔猪生长[10];饲粮添加100 mg/kg CS可缓解ETEC攻毒导致的仔猪生长缓慢、促进肠道健康[11];饲粮添加15 mg/kg CS可缓解脂多糖(lipopolysaccharide,LPS)诱导的蛋鸡肠道屏障损伤和氧化免疫应激[12]。但CS对蛋鸡沙门氏菌感染的预防作用研究鲜少有报道。因此,本试验通过构建SP感染蛋鸡模型,从蛋品质、血清抗氧化指标、肝脏功能、机体炎症反应和免疫功能以及肝脏和输卵管膨大部病理变化等方面,探讨饮水添加CS对SP致蛋鸡肝脏损伤及输卵管炎症的缓解作用,为CS在防治沙门氏菌感染蛋鸡的应用方面提供理论基础和试验数据。

1 材料与方法

1.1 试验材料

本试验所用CS(分子质量100 ku)购自厦门某科技有限公司;SP(菌种编号:CVCC521)购自国家兽医微生物菌种保藏中心。

1.2 试验设计

试验采用单因素随机设计,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)。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[13],CON组每只试验鸡口服1 mL生理盐水,攻毒前4 h所有组试验鸡禁食禁水;第2次攻毒结束后,立即在CS组饮水中添加0.4% CS[14],且连续7 d服用含CS的水。

1.3 基础饲粮

3组试验鸡全程饲喂相同的基础饲粮,基础饲粮为粉状玉米-豆粕型配合饲料,参照《鸡饲养标准》(NY/T 33—2004)并结合《海兰褐产蛋鸡饲养手册》配制,其组成及营养水平见表1
表1 基础饲粮组成及营养水平(风干基础)

Table 1 Composition and nutrient levels of the basal diet (air-dry basis)%

原料
Ingredients
含量
Content
营养水平
Nutrient levels2)
含量
Content
玉米Corn 63.55 代谢能ME/(MJ/kg) 11.24
豆粕Soybean meal 26.00 粗蛋白质CP 16.52
植酸酶Phytase 0.02 赖氨酸Lys 0.89
氯化胆碱Choline chloride 0.12 蛋氨酸Met 0.39
DL-蛋氨酸DL-methionine 0.12 苏氨酸Thr 0.65
磷酸氢钙CaHPO4 0.96 异亮氨酸Ile 0.71
石粉Limestone 8.80 蛋氨酸+半胱氨酸Met+Cys 0.68
氯化钠NaCl 0.30 钙Ca 3.37
预混料Premix1) 0.13 总磷TP 0.34
合计Total 100.00

1)预混料为每千克饲粮提供 The premix provided the following per kg of the diet:VA 12 500 IU,VD3 4 125 IU,VE 15 IU,VK3 2.0 mg,VB1 1.0 mg,VB2 8.5 mg,VB6 8.0 mg,VB12 5 mg,泛酸钙 calcium pantothenate 50.0 mg,烟酸 nicotinic acid 32.5 mg,生物素 biotin 2 mg,叶酸 folic acid 5 mg,胆碱 choline 500 mg,Fe 60 mg,Cu 8 mg,I 1 mg,Zn 66 mg,Mn 65 mg,Se 0.3 mg。

2)代谢能为计算值,其余为实测值。ME was a calculated value, while the others were measured values.

1.4 饲养管理

本试验在中国农业科学院饲料研究所涿州蛋鸡试验基地进行,采用3层阶梯笼养,每笼独立饮水,试验期间鸡只自由采食和饮水。光照时长为16 h/d,光照强度为15 lx,相对湿度为50%~80%,平均温度为30 ℃,采用自然通风辅以水帘负压纵向通风。常规免疫接种。

1.5 指标测定

1.5.1 产蛋性能

试验期间,每日以重复为单位记录各组蛋鸡日产蛋量,并根据记录的数据计算产蛋率。

1.5.2 蛋品质

分别于试验第1天、第3天和第7天,每重复随机选取3枚蛋,采用SONOVA蛋品质自动分析仪(Orka Technology Ltd.)测定蛋白高度、哈氏单位和蛋黄颜色;采用蛋壳强度分析仪(Orka Technology Ltd.)测定蛋壳强度;采用蛋壳厚度测定仪(Orka Technology Ltd.)测定蛋壳厚度;采用数显游标卡尺测定长径和短径值,并计算蛋形指数(长径值/短径值)。

1.5.3 肝脏指数

试验第7天,禁食8 h后对试验鸡进行称重,每重复随机选取2羽鸡处死,取肝脏称重,计算肝脏指数,计算公式为:

肝脏指数(%)=100×肝脏重量(g)/活体重(g)。

1.5.4 血清生化指标

试验第7天,每重复随机选取2羽鸡,颈静脉采血,离心得到血清,于-20 ℃保存。采用全自动血液生化分析仪(M4)测定血清谷草转氨酶(AST)、谷丙转氨酶(ALT)活性以及总蛋白(TP)和白蛋白(ALB)含量。测定试剂盒均购自上海科华生物工程股份有限公司。

1.5.5 血清抗氧化指标

按照试剂盒(南京建成生物工程研究所)说明书,测定血清超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性以及丙二醛(MDA)含量。

1.5.6 血浆炎性因子、免疫球蛋白和SP抗体(SP-Ab)含量测定

试验第7天,每重复随机选取2羽鸡,颈静脉采血制备血浆,按照试剂盒(上海酶联生物科技有限公司)说明书测定血浆分泌型免疫球蛋白A(sIgA)、免疫球蛋白A(IgA)、免疫球蛋白G(IgG)、白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)和SP-Ab含量。

1.5.7 临床症状及肝脏和输卵管膨大部组织病理学观察

攻毒结束后,每隔12 h观察鸡群典型临床症状。试验第7天,每重复随机选取2羽鸡处死,取肝脏和输卵管膨大部,分别剪取1 cm2组织浸泡于福尔马林溶液中固定,制备石蜡切片,并进行苏木精-伊红(HE)染色,在光学显微镜下观察组织病理学变化。

1.6 数据分析

试验数据采用Excel 2019进行初步整理,然后采用SAS 9.2统计软件进行单因素方差分析(one-way ANOVA),效应显著者采用Duncan氏法进行多重比较,结果用“平均值±标准误”表示,采用GraphPad Prism 6.0软件对试验数据进行分析并做柱形图,P<0.05表示差异显著。

2 结果与分析

2.1 CS对SP攻毒蛋鸡产蛋性能的影响

表2可知,与CON组相比,SP组蛋鸡产蛋率显著降低(P<0.05),CS组产蛋率无显著差异(P>0.05);与SP组相比,CS组产蛋率显著提高(P<0.05)。
表2 CS对SP攻毒蛋鸡产蛋性能的影响

Table 2 Effects of CS on laying performance of laying hens challenged with SP%

项目
Item
组别Groups P
P-value
CON SP CS
产蛋率Laying rate 92.86±0.04a 66.67±0.02b 85.71±0.04a 0.006

同行数据肩标无字母或相同字母表示差异不显著(P>0.05),不同字母表示差异显著(P<0.05)。下表同。

In the same row, values with no letter or the same letter superscripts mean no significant difference (P>0.05), while with different letter superscripts mean significant difference (P<0.05). The same as below.

2.2 CS对SP攻毒蛋鸡蛋品质的影响

表3可知,与CON组相比,SP组第1天和第3天蛋壳强度显著降低(P<0.05),SP组和CS组第1天、第3天和第7天蛋白高度、蛋黄颜色、哈氏单位、蛋壳厚度和蛋形指数均无显著差异(P>0.05);与SP组相比,CS组第3天和第7天蛋壳强度显著提高(P<0.05)。
表3 CS对SP攻毒蛋鸡蛋品质的影响

Table 3 Effects of CS on egg quality of laying hens challenged with SP

项目
Items
时间
Time
组别Groups P
P-value
CON SP CS
蛋白高度 第1天Day 1 7.80±0.21 6.94±0.48 7.14±0.29 0.223
Albumen height/mm 第3天Day 3 7.68±0.25 7.44±0.27 7.84±0.52 0.746
第7天Day 7 7.70±0.50 7.50±0.23 8.10±0.31 0.516
蛋黄颜色 第1天Day 1 7.20±0.37 6.20±0.49 7.20±0.37 0.189
Yolk color 第3天Day 3 7.20±0.20 6.40±0.51 6.80±0.37 0.367
第7天Day 7 6.80±0.37 6.40±0.51 7.40±0.25 0.232
哈氏单位 第1天Day 1 84.20±3.40 76.10±3.35 81.52±1.95 0.189
Haugh unit 第3天Day 3 85.78±2.42 81.64±4.47 88.74±3.31 0.384
第7天Day 7 89.20±3.04 82.26±2.37 89.48±2.20 0.119
蛋壳厚度 第1天Day 1 0.41±0.01 0.40±0.00 0.41±0.01 0.630
Eggshell thickness/mm 第3天Day 3 0.41±0.01 0.39±0.01 0.41±0.01 0.405
第7天Day 7 0.39±0.01 0.39±0.01 0.41±0.01 0.235
蛋壳强度 第1天Day 1 38.55±0.33a 37.08±0.28b 38.22±0.51ab 0.047
Eggshell strength/(N/cm2) 第3天Day 3 38.48±0.48a 36.73±0.57b 39.04±0.62a 0.032
第7天Day 7 38.87±0.22ab 37.97±0.50b 39.80±0.29a 0.012
蛋形指数 第1天Day 1 1.31±0.02 1.28±0.02 1.29±0.02 0.685
Egg shape index 第3天Day 3 1.30±0.01 1.27±0.01 1.27±0.01 0.082
第7天Day 7 1.28±0.01 1.26±0.01 1.28±0.01 0.185

2.3 CS对SP攻毒蛋鸡肝脏指数的影响

表4可知,与CON组相比,CS组蛋鸡肝脏指数显著提高(P<0.05),SP组活体重、肝脏重量和肝脏指数均无显著差异(P>0.05);与SP组相比,CS组肝脏指数显著提高(P<0.05),活体重和肝脏重量无显著差异(P>0.05)。
表4 CS对SP攻毒蛋鸡肝脏指数的影响

Table 4 Effects of CS on liver index of laying hens challenged with SP

项目
Items
组别Groups P
P-value
CON SP CS
活体重Live body weight/kg 1.88±0.04 1.83±0.04 1.73±0.06 0.081
肝脏重量Liver weight/g 29.37±1.35 28.73±0.96 31.15±1.13 0.344
肝脏指数Liver index/% 1.56±0.07b 1.57±0.05b 1.80±0.05a 0.019

2.4 CS对SP攻毒蛋鸡血清生化指标的影响

图1可知,与CON组相比,SP组蛋鸡血清ALB含量和AST活性显著提高(P<0.05),血清TP含量和ALT活性无显著差异(P>0.05);CS组血清TP和ALB含量显著提高(P<0.05)。与SP组相比,CS组血清AST活性显著降低(P<0.05),血清TP和ALB含量以及ALT活性无显著差异(P>0.05)。
图1 CS对SP攻毒蛋鸡血清生化指标的影响

数据柱形标注不同小写字母表示差异显著(P<0.05)。下图同。

Fig.1 Effects of CS on serum biochemical indices of laying hens challenged with SP

Value columns with different small letters mean significant difference (P<0.05). The same as below.

2.5 CS对SP攻毒蛋鸡血清抗氧化指标的影响

图2可知,与CON组相比,SP组蛋鸡血清MDA含量显著提高(P<0.05),血清GSH-Px和SOD活性无显著差异(P>0.05);CS组血清GSH-Px和SOD活性显著提高(P<0.05),血清MDA含量无显著差异(P>0.05)。与SP组相比,CS组血清GSH-Px和SOD活性显著提高(P<0.05),血清MDA含量显著降低(P<0.05)。
图2 CS对SP攻毒蛋鸡血清抗氧化指标的影响

Fig.2 Effects of CS on serum antioxidant indices of laying hens challenged with SP

2.6 CS对SP攻毒蛋鸡血浆炎性因子、免疫球蛋白和SP-Ab含量的影响

图3可知,与CON组相比,SP组血浆IL-1β含量显著提高(P<0.05),血浆IL-6和TNF-α含量显著降低(P<0.05);CS组血浆IL-6含量显著降低(P<0.05)。与SP组相比,CS组血浆IL-1β、IL-6和TNF-α含量均无显著差异(P>0.05)。
图3 CS对SP攻毒蛋鸡血浆炎性因子含量的影响

Fig.3 Effects of CS on plasma inflammatory factor contents of laying hens challenged with SP

图4可知,与CON组相比,SP组和CS组血浆SP-Ab含量显著提高(P<0.05),血浆IgA、IgG和sIgA含量均无显著差异(P>0.05);与SP组相比,CS组血浆SP-Ab含量显著提高(P<0.05),血浆IgA、IgG和sIgA含量均无显著差异(P>0.05)。
图4 CS对SP攻毒蛋鸡血浆免疫球蛋白和SP-Ab含量的影响

Fig.4 Effects of CS on plasma immunoglobulin and SP-Ab contents of laying hens challenged with SP

2.7 CS对SP攻毒蛋鸡临床症状及肝脏和输卵管膨大部组织病理变化的影响

本试验中,攻毒直至试验结束,试验鸡无死亡,攻毒后12 h,蛋鸡表现出白痢、嗜睡、精神不佳、羽毛松乱无光泽以及采食量减少等典型临床症状,表明攻毒造模成功。攻毒后饮用含CS的水,从第3天开始,试验鸡症状逐步缓解。
图5可知,CON组蛋鸡肝脏组织被膜结构清晰,肝细胞结构完整,细胞核清晰,无明显变性;肝窦无明显扩张或挤压,肝索排列整齐,相邻肝小叶之间的汇管区无明显异常,未见明显病理改变。SP组肝脏组织被膜结构清晰,小叶内可见少量的肝细胞坏死崩解,核固缩,伴有淋巴细胞炎性浸润灶,少量肝细胞脂肪变性,肝细胞的胞质被脂肪取代,胞质内可见大小不一的空泡,汇管区无明显异常。CS组肝脏组织被膜结构清晰,肝细胞圆润、饱满,肝窦无明显扩张或挤压,汇管区血管周围可见少量淋巴细胞小灶性浸润,未见其他病理变化。
图5 CS对SP攻毒蛋鸡肝脏组织病理变化的影响

Fig.5 Effects of CS on liver histopathological changes of laying hens challenged with SP

图6可知,CON组蛋鸡输卵管膨大部组织在低倍镜下可见绒毛膜上皮层和固有层结构完整,无明显病变;在高倍镜下可见分泌细胞和柱状纤毛细胞有序排列。SP组蛋鸡输卵管膨大部组织在低倍镜下可见绒毛膜碎裂,在高倍镜下可见多处嗜碱性蓝染的炎性细胞浸润灶和多处脂肪变性的分泌细胞。CS组蛋鸡输卵管膨大部组织在高倍镜下绒毛膜结构完整且清晰;在低倍镜下可见零星分泌细胞胞浆嗜酸性,细胞核完整,未见其他明显病理变化。
图6 CS对SP攻毒蛋鸡输卵管膨大部组织病理变化的影响

Fig.6 Effects of CS on oviduct magnum histopathological changes of laying hens challenged with SP

3 讨论

3.1 CS对SP攻毒蛋鸡产蛋性能的影响

沙门氏菌攻毒可显著降低蛋鸡产蛋率和蛋重[15],CS作为天然抗菌剂对沙门氏菌有良好的抗菌作用[16]。研究表明,饲粮添加500 mg/kg CS可显著提高蛋鸡产蛋量[17]。本研究表明,饮水中添加0.4% CS对SP有较好的抑制作用,可缓解因SP攻毒导致的蛋鸡产蛋率的降低。由此可知,SP攻毒导致产蛋率降低和CS对其的缓解效果可能与CS的强抗菌作用有关,具体影响机制还需要进一步研究。

3.2 CS对SP攻毒蛋鸡蛋品质的影响

SP可定植于肠道,并突破肠道屏障随血液传递至肝脏、脾脏及生殖道定植[18]。SP可通过饮水经口感染鸡只,影响蛋鸡生产性能。本研究模拟SP饮水感染,采用口服攻毒方式造模,攻毒后蛋鸡出现食欲不振、精神不佳、嗜睡、饮水量减少、排白色稀便及糊肛等临床症状,但未死亡,表明在本试验条件下SP感染造模成功。通过测定肝功能敏感指标(血清AST和ALT活性),联合肝脏组织病理学观察,可证明口服沙门氏菌造成蛋鸡急性肝脏损伤。Li等[19]研究表明,沙门氏菌通过细菌异位和相关内毒素引起肠道炎症和氧化应激,肠道和肝脏中免疫系统的激活会加剧大鼠急性肝脏损伤。细菌入侵引起的急性肝脏损伤影响蛋品质,研究表明,蛋壳强度与子宫部蛋壳钙化相关的离子转运功能及肠道对营养物质的消化吸收密切相关[20],但鲜有研究分析肝脏等器官组织对蛋壳强度的影响。研究表明,肝脏损伤会导致营养物质的摄取和吸收功能受损,影响钙和磷吸收,导致蛋壳强度的下降[21];SP攻毒可导致蛋壳强度下降[13],沙门氏菌感染上调了肝脏哺乳动物雷帕霉素靶蛋白(mTOR)信号通路的基因表达,影响蛋壳强度[22],上述结果与本研究一致。CS上有大量带正电荷的氨基基团,可与细菌细胞膜上的负电结合,破坏细菌细胞膜完整性,达到抑菌效果[23]。本研究团队前期体外试验结果表明,0.4% CS可有效抑制SP;饲粮添加125 mg/kg CS显著提高蛋鸡蛋壳强度[24],这均与本研究结果相似。综上可知,饮水中添加0.4% CS可缓解因SP攻毒导致的蛋壳强度下降,其原因可能是CS能够通过抑制沙门氏菌增殖,缓解因感染引起的肝脏损伤和炎症反应,从而改善蛋壳品质。

3.3 CS对SP攻毒蛋鸡肝脏损伤的影响

血清生化指标是反映机体代谢、营养情况及健康情况的敏感指标。SP进入机体后分泌LPS,后者可随血液进入内脏器官,产生毒害作用,造成肝脏等器官损伤。研究表明,SP感染蛋鸡后,主要定植部位为肝脏和脾脏,其次为心脏和卵巢,剖检发现上述器官均存在肉眼可见的病理变化[25]。本研究制作了肝脏组织病理切片,在光学显微镜下观察到SP组肝脏存在少量的肝细胞坏死崩解,核固缩,且伴有淋巴细胞炎性浸润灶等病理现象。肝细胞受损后,大量AST从细胞释放,进入血液中,引起血清AST活性及TP和ALB含量提高,表明本试验模型中,SP攻击肝脏并引起了肝脏炎症,这与Chen等[26]的研究结果一致。饮水中添加CS后,肝细胞圆润、饱满,炎性小灶数量减少,血清AST活性显著降低,且肝脏指数以及血清TP和ALB含量显著高于CON组。饮水中添加CS后第7天,肝脏指数显著提高,这可能与CS能促进肝细胞的存活,加快肝细胞增殖分化和肝脏损伤修复有关[27-28]。与之相似的是,Xu等[24]研究表明,饲粮添加125 mg/kg CS可显著提高蛋鸡血清ALB含量。总之,CS对肝细胞损伤具有一定的保护作用,这可能与CS缓解机体炎症反应、促进肝脏损伤后修复有关,但其具体作用机制尚不明确,有待进一步研究。

3.4 CS对SP攻毒蛋鸡血清抗氧化指标的影响

氧化应激是机体活性氧(ROS)含量和内源性抗氧化能力失衡所致,此时细胞抗氧化能力不足,细胞内毒性ROS含量增加,产生氧自由基,使生物大分子受到攻击,从而引起细胞和组织损伤[29]。MDA是机体脂质过氧化过程的最终产物,具有细胞毒性,其含量可直接反映出脂质过氧化和细胞损伤程度。CS是具有强抗氧化能力的物质,饲粮添加500 mg/kg CS可提高蛋鸡血清、肝脏和十二指肠组织的抗氧化能力,其作用机制可能通过上调核因子E2相关因子(Nrf2)的表达来增强Nrf2介导的Ⅱ期解毒酶的基因表达和活性,从而提高蛋鸡的抗氧化能力[17]。Xu等[24]研究表明,饲粮添加125 mg/kg CS可显著提高蛋鸡血清总抗氧化能力(T-AOC),饲粮添加75 mg/kg可显著降低血清MDA含量。在本试验中,SP感染使蛋鸡血清MDA含量显著提高,而饮水中添加0.4% CS使蛋鸡血清MDA含量显著降低,血清GSH-Px和SOD活性显著提高。这与Wu等[30]和Tao等[31]的研究结果相似。本试验结果表明,SP攻毒造成了蛋鸡机体MDA蓄积,机体抗氧化能力受损,而饮水种添加CS可缓解SP攻毒所导致的蛋鸡氧化应激。

3.5 CS对SP攻毒蛋鸡炎症反应和免疫功能的影响

复杂的细胞因子网络可调节宿主的免疫反应,增强对细菌感染的抵抗力并降低机体疾病的易感性。炎症反应是机体对外界刺激产生的防御性反应,当受到负面刺激时,机体会通过炎症反应来促进组织恢复。白细胞是机体抵御细菌入侵的“卫士”,其分为粒细胞、单核细胞和淋巴细胞3大类,IL-1β是由单核细胞产生的促炎细胞因子。当机体受到SP感染时,会引起炎症反应和免疫功能的激活,本研究表明,与CON组相比,SP组蛋鸡血浆IL-1β和SP-Ab含量显著提高,机体发生炎症反应进一步证实了SP感染模型造模成功。王晓辰等[32]研究表明,CS可提高雏鸡血浆IgA、IgG、免疫球蛋白M(IgM)和sIgA含量,与本试验结果趋势相似;SP感染后在饮水中添加CS可显著提高血浆SP-Ab含量,可能与CS促进机体免疫应答有关。组织病理切片观察发现,SP组蛋鸡肝小叶内可见少量肝细胞坏死崩解,核固缩,且伴有淋巴细胞炎性浸润灶,少量肝细胞脂肪变性,这与余庆[33]的研究结果一致;饮水中添加CS后,肝脏炎性灶明显减少,表明CS具有一定的抗炎作用。IL-6是一种多功能细胞因子,在宿主防御中发挥重要作用。当机体受到细菌感染或组织损伤时,单核细胞和巨噬细胞会迅速产生IL-6,并通过激活免疫系统共同修复组织损伤[34]IL-6的表达会导致体内外沙门氏菌侵袭性显著降低[35]。也有文献表明,IL-6可控制促炎细胞因子水平,在局部和全身急性炎症反应中发挥至关重要的抗炎作用[36]。值得注意的是,本研究中,SP攻毒后蛋鸡血浆IL-6和TNF-α含量显著降低,提示SP组细菌侵袭性仍较高,这可能与核因子-κB(NF-κB)信号通路的调控作用有关,NF-κB可诱导肿瘤坏死因子(TNF)和IL-6的释放[37-38],但具体影响机制尚不明确。SP感染后在饮水中添加CS使得血浆IL-6和TNF-α含量均有上升的趋势,这与Xiao等[39]的研究结果一致。从逻辑上讲,细菌感染导致Toll样受体4(TLR4)蛋白表达上调,使得TLR4信号通路受到抑制,其下游细胞因子IL-6和TNF-α含量降低,而补充CS可促进IL-6的表达,但TLR4需要一定时间才能激活其下游信号通路。

3.6 CS对SP攻毒蛋鸡输卵管膨大部炎症的影响

蛋鸡输卵管是沙门氏菌定植入侵的重要靶器官,沙门氏菌可通过其致病岛侵入并存活于蛋鸡输卵管上皮细胞内[40],引起炎症反应,且可到达鸡蛋表面和蛋内,影响鸡蛋品质和蛋鸡生产性能[41],其对输卵管的损害可能与普遍胁迫蛋白B(uspBi)和普遍胁迫蛋白BA(uspBA)有关[42]。有报道表明,攻毒沙门氏菌2 d内,蛋鸡肝脏、脾脏、心脏、胆囊、卵巢和输卵管组织中均有沙门氏菌检出[43];给予蛋鸡口服1×109 CFU/mL SP后,输卵管沙门氏菌检出率达到66.67%,高于空白对照组[44],这表明SP可定植于输卵管中[45]。本研究中,通过组织病理切片观察发现,SP组蛋鸡输卵管膨大部绒毛膜碎裂,在高倍镜下可见多处嗜碱性蓝染的炎性细胞浸润灶,表明SP在输卵管膨大部定植并刺激输卵管产生炎症;同时,SP组蛋白高度和哈氏单位有下降趋势,这可能与输卵管的炎症状态有关。值得注意的是,蛋鸡饮用含CS的水后,输卵管炎性病灶显著减少,这表明在饮水中添加CS可缓解因SP感染导致的蛋鸡输卵管炎症,有利于维持蛋鸡健康状态。

4 结论

本试验条件下,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。
[1]
徐亚慧. 马齿苋发酵物对雏鸡白痢的防治及肠道菌群的影响研究[D]. 硕士学位论文. 保定: 河北农业大学, 2018:1-4.

XU Y H. Study on the control effect of purslane fermented material on pullorum disease and the influence of intestinal flora[D]. Master’s Thesis. Baoding: Hebei Agricultural University, 2018:1-4. (in Chinese)

[2]
张婷婷. 乳酸改性沸石对感染沙门氏菌肉鸡的影响研究[D]. 硕士学位论文. 南京: 南京农业大学, 2011:1-2.

ZHANG T T. Effects of lactic acid-modified zeolite on broilers after Salmonella pullorum infection[D]. Master’s Thesis. Nanjing: Nanjing Agricultural University, 2011:1-2. (in Chinese)

[3]
BARROW P A, FREITAS NETO O C. Pullorum disease and fowl typhoid-new thoughts on old diseases:a review[J]. Avian Pathology, 2011, 40(1):1-13.

DOI

[4]
刘洋, 严专强, 王占新, 等. 69株鸡白痢沙门氏菌的分离鉴定及耐药性分析[J]. 家禽科学, 2018(11):43-45.

LIU Y, YAN Z Q, WANG Z X, et al. Isolation,identification and drug resistance analysis of 69 strains of Salmonella pullorum from chicken[J]. Poultry Science, 2018(11):43-45. (in Chinese)

[5]
张二红, 潘晓亮, 王新峰, 等. 壳聚糖在家禽生产中的研究进展[J]. 中国家禽, 2014, 36(15):37-39.

ZHANG E H, PAN X L, WANG X F, et al. Research progress of chitosan in poultry production:a review[J]. China Poultry, 2014, 36(15):37-39. (in Chinese)

[6]
ZHU L, WANG S Q, CAI Y, et al. Effects of five prebiotics on growth,antioxidant capacity,non-specific immunity,stress resistance,and disease resistance of juvenile hybrid grouper (Epinephelus fuscoguttatus ♀×Epinephelus lanceolatus ♂)[J]. Animals, 2023, 13(4):754.

DOI

[7]
李小芳. 壳聚糖抑菌活性及机理研究[D]. 硕士学位论文. 兰州: 兰州大学, 2009:1-8.

LI X F. Study on the antimicrobial activity and mechanism of chitosan[D]. Master’s Thesis. Lanzhou: Lanzhou University, 2009:1-8. (in Chinese)

[8]
丁科, 徐倩倩, 夏文锐, 等. 低聚壳聚糖在家禽生产中的应用[J]. 饲料工业, 2019, 40(10):17-21.

DING K, XU Q Q, XIA W R, et al. Application of chitosan oligosaccharide in poultry production[J]. Feed Industry, 2019, 40(10):17-21. (in Chinese)

[9]
GUAN Z W, FENG Q. Chitosan and chitooligosaccharide:the promising non-plant-derived prebiotics with multiple biological activities[J]. International Journal of Molecular Sciences, 2022, 23(12):6761.

DOI

[10]
XIAO D F, TANG Z R, YIN Y L, et al. Effects of dietary administering chitosan on growth performance,jejunal morphology,jejunal mucosal sIgA,occludin,claudin-1 and TLR4 expression in weaned piglets challenged by enterotoxigenic Escherichia coli[J]. International Immunopharmacology, 2013, 17(3):670-676.

DOI

[11]
ZHANG J, WAN J, WU G Z, et al. Low-molecular-weight chitosan relieves enterotoxigenic Escherichia coli-induced growth retardation in weaned pigs[J]. International Immunopharmacology, 2020, 78:105798.

DOI

[12]
GU Y F, CHEN Y P, JIN R, et al. Dietary chitooligosaccharide supplementation alleviates intestinal barrier damage,and oxidative and immunological stress in lipopolysaccharide-challenged laying hens[J]. Poultry Science, 2022, 101(4):101701.

DOI

[13]
WANG W W, JIA H J, ZHANG H J, et al. Supplemental plant extracts from Flos lonicerae in combination with Baikal skullcap attenuate intestinal disruption and modulate gut microbiota in laying hens challenged by Salmonella pullorum[J]. Frontiers in Microbiology, 2019, 10:1681.

DOI

[14]
MENCONI A, PUMFORD N R, MORGAN M J, et al. Effect of chitosan on Salmonella typhimurium in broiler chickens[J]. Foodborne Pathogens and Disease, 2014, 11(2):165-169.

DOI

[15]
GUO F S, GENG Y Q, ABBAS W, et al. Vitamin D3 nutritional status affects gut health of Salmonella-challenged laying hens[J]. Frontiers in Nutrition, 2022, 9:888580.

DOI

[16]
IBAÑEZ-PEINADO D, UBEDA-MANZANARO M, MARTÍNEZ A, et al. Antimicrobial effect of insect chitosan on Salmonella typhimurium,Escherichia coli O157∶H7 and Listeria monocytogenes survival[J]. PLoS One, 2020, 15(12):e0244153.

[17]
LI Y H, ZHANG Q Y, FENG Y H, et al. Dietary chitosan supplementation improved egg production and antioxidative function in laying breeders[J]. Animals, 2022, 12(10):1225.

DOI

[18]
CHALGHOUMI R, MARCQ C, THÉWIS A, et al. Effects of feed supplementation with specific hen egg yolk antibody (immunoglobin Y) on Salmonella species cecal colonization and growth performances of challenged broiler chickens[J]. Poultry Science, 2009, 88(10):2081-2092.

DOI

[19]
LI Y T, YU C B, YAN D, et al. Effects of Salmonella infection on hepatic damage following acute liver injury in rats[J]. Hepatobiliary & Pancreatic Diseases International, 2016, 15(4):399-405.

[20]
CHEN X, MA X M, YANG C W, et al. Low level of dietary organic trace elements improve the eggshell strength,trace element utilization,and intestinal function in late-phase laying hens[J]. Frontiers in Veterinary Science, 2022, 9:903615.

DOI

[21]
LIU X T, LIN X, MI Y L, et al. Age-related changes of yolk precursor formation in the liver of laying hens[J]. Journal of Zhejiang University:Science B (Biomedicine & Biotechnology), 2018, 19(5):390-399.

[22]
HAN G P, KIM J H, KIM J M, et al. Transcriptomic analysis of the liver in aged laying hens with different eggshell strength[J]. Poultry Science, 2023, 102(1):102217.

DOI

[23]
ABD EL-HACK M E, EL-SAADONY M T, SHAFI M E, et al. Antimicrobial and antioxidant properties of chitosan and its derivatives and their applications:a review[J]. International Journal of Biological Macromolecules, 2020, 164:2726-2744.

DOI

[24]
XU Q Q, AZZAM M M M, ZOU X T, et al. Effects of chitooligosaccharide supplementation on laying performance,egg quality,blood biochemistry,antioxidant capacity and immunity of laying hens during the late laying period[J]. Italian Journal of Animal Science, 2020, 19(1):1180-1187.

DOI

[25]
PINHEIRO L A, DE OLIVEIRA G H, BERCHIERI A,Jr. Experimental Salmonella enterica serovar pullorum infection in two commercial varieties of laying hens[J]. Avian Pathology, 2001, 30(2):129-133.

DOI

[26]
CHEN F, ZHANG H, DU E C, et al. Supplemental magnolol or honokiol attenuates adverse effects in broilers infected with Salmonella pullorum by modulating mucosal gene expression and the gut microbiota[J]. Journal of Animal Science and Biotechnology, 2021, 12(1):87.

DOI

[27]
黄坤, 刘承利, 韩公海, 等. 脂肪间充质干细胞复合多孔壳聚糖微球修复大鼠肝损伤[J]. 中国组织工程研究, 2019, 23(5):716-722.

HUANG K, LIU C L, HAN G H, et al. Repair of liver injury in rats by adipose-derived mesenchymal stem cells combined with porous chitosan microspheres[J]. Chinese Journal of Tissue Engineering Research, 2019, 23(5):716-722. (in Chinese)

[28]
王永恒, 党奇峰, 陈军, 等. 氨基葡萄糖、N-乙酰氨基葡萄糖和小分子壳聚糖对C2H5OH和CCl4所致肝细胞损伤的预防和修复作用[J]. 功能材料, 2011, 42(7):1297-1300.

WANG Y H, DANG Q F, CHEN J, et al. Preventive and recoverable effects of GlcNH2,GlcNAc and low molecular CS against C2H5OH or CCl4-induced hepatocytes damage[J]. Journal of Functional Materials, 2011, 42(7):1297-1300. (in Chinese)

[29]
SPECTOR A. Review:oxidative stress and disease[J]. Journal of Ocular Pharmacology and Therapeutics, 2000, 16(2):193-201.

DOI

[30]
WU Q J, ZHENG X C, WANG T, et al. Effect of dietary oridonin supplementation on growth performance,gut health,and immune response of broilers infected with Salmonella pullorum[J]. Irish Veterinary Journal, 2018, 71:16.

DOI

[31]
TAO W J, WANG G, PEI X, et al. Chitosan oligosaccharide attenuates lipopolysaccharide-induced intestinal barrier dysfunction through suppressing the inflammatory response and oxidative stress in mice[J]. Antioxidants, 2022, 11(7):1384.

DOI

[32]
王晓辰, 李福伟, 朱连勤, 等. 硒化壳寡糖对雏鸡生长性能与免疫功能的影响[J]. 中国畜牧杂志, 2023, 59(3):224-229.

WANG X C, LI F W, ZHU L Q, et al. Effects of selenide chitosan oligosaccharides on growth performance and immune function in chickens[J]. Chinese Journal of Animal Science, 2023, 59(3):224-229. (in Chinese)

[33]
余庆. 鸡白痢沙门氏菌毒力因子分析及对SPF鸡致病性研究[D]. 硕士学位论文. 武汉: 华中农业大学, 2018:6-8.

YU Q. Research on virulence factors and pathogenicity of Salmonella pullorum in SPF chickens[D]. Master’s Thesis. Wuhan: Huazhong Agricultural University, 2018:6-8. (in Chinese)

[34]
TANAKA T, NARAZAKI M, MASUDA K, et al. Regulation of IL-6 in immunity and diseases[J]. Advances in Experimental Medicine and Biology, 2016, 941:79-88.

PMID

[35]
DUNSTAN S J, RAMSAY A J, STRUGNELL R A. Studies of immunity and bacterial invasiveness in mice given a recombinant Salmonella vector encoding murine interleukin-6[J]. Infection and Immunity, 1996, 64(7):2730-2736.

DOI

[36]
XING Z, GAULDIE J, COX G, et al. IL-6 is an antiinflammatory cytokine required for controlling local or systemic acute inflammatory responses[J]. Journal of Clinical Investigation, 1998, 101(2):311-320.

DOI PMID

[37]
FINAMORE E, VITIELLO M, D’ISANTO M, et al. Evidence for IL-6 promoter nuclear activation in U937 cells stimulated with Salmonella enterica serovar typhimurium porins[J]. European Cytokine Network, 2009, 20(3):140-147.

DOI

[38]
VANDEN BERGHE W, VERMEULEN L, DE WILDE G, et al. Signal transduction by tumor necrosis factor and gene regulation of the inflammatory cytokine interleukin-6[J]. Biochemical Pharmacology, 2000, 60(8):1185-1195.

DOI PMID

[39]
XIAO D F, WANG Y F, LIU G, et al. Effects of chitosan on intestinal inflammation in weaned pigs challenged by enterotoxigenic Escherichia coli[J]. PloS One, 2014, 9(8):e104192.

DOI

[40]
RASPOET R, APPIA-AYME C, SHEARER N, et al. Microarray-based detection of Salmonella enterica serovar enteritidis genes involved in chicken reproductive tract colonization[J]. Applied and Environmental Microbiology, 2014, 80(24):7710-7716.

DOI

[41]
樊世杰, 李东锋, 段忠意, 等. 肠炎沙门氏菌污染饲料对鸡蛋安全的影响[J]. 中国家禽, 2012, 34(7):11-15.

FAN S J, LI D F, DUAN Z Y, et al. Infection status of eggs after hens infected Salmonella enteritidis through feed intake[J]. China Poultry, 2012, 34(7):11-15. (in Chinese)

[42]
RASPOET R, GANTOIS I, DEVLOO R, et al. Salmonella enteritidis universal stress protein (usp) gene expression is stimulated by egg white and supports oviduct colonization and egg contamination in laying hens[J]. Veterinary Microbiology, 2011, 153(1/2):186-190.

DOI

[43]
WIGLEY P, BERCHIERI A,Jr, PAGE K L, et al. Salmonella enterica serovar pullorum persists in splenic macrophages and in the reproductive tract during persistent,disease-free carriage in chickens[J]. Infection and Immunity, 2001, 69(12):7873-7879.

DOI

[44]
KELLER L H, BENSON C E, KROTEC K, et al. Salmonella enteritidis colonization of the reproductive tract and forming and freshly laid eggs of chickens[J]. Infection and Immunity, 1995, 63(7):2443-2449.

DOI

[45]
贾红杰. 山黄粉和黄芪多糖对蛋鸡生产性能和免疫机能的影响[D]. 硕士学位论文. 兰州: 甘肃农业大学, 2019:29-30.

JIA H J. Effects of Flos lonicerae-Baikal skullcap and Astragalus polysacharin on production performance and immune function of laying hens[D]. Master’s Thesis. Lanzhou: Gansu Agricultural University, 2019:29-30. (in Chinese)

文章导航

/