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1.
试验以产气荚膜梭菌感染肉仔鸡建立坏死性肠炎模型,研究发酵乳杆菌和凝结芽孢杆菌对感染肉鸡生长性能和肠道健康的影响。将336只1日龄爱拔益加肉仔鸡随机分成4个处理组,每个处理6个重复。4个处理组分别为对照组、感染组、感染+LF组(日粮添加1×10~9 CFU/kg发酵乳杆菌)、感染+BC组(日粮添加1×10~(10) CFU/kg凝结芽孢杆菌)。所有感染肉鸡在14～21 d经口接种A型产气荚膜梭菌。试验期为28 d。结果显示:与对照组相比,灌服产气荚膜梭菌显著降低22～28 d肉鸡的日均采食量(P0.05),显著增加28 d十二指肠和空肠损伤评分(P0.05),显著提高21 d肉鸡盲肠的产气荚膜梭菌和大肠杆菌数量,显著降低28 d回肠产气荚膜梭菌数量(P0.05)。与感染组相比,日粮添加发酵乳杆菌显著提高21 d肉鸡回肠的乳杆菌属数量(P0.05),显著降低21 d盲肠大肠杆菌的数量(P0.05);日粮添加凝结芽孢杆菌显著降低28 d肉鸡十二指肠损伤评分(P0.05),显著降低21 d十二指肠隐窝深度(P0.05),显著提高21 d空肠绒毛高度与隐窝深度的比值(P0.05),显著降低21 d肉鸡回肠和盲肠的大肠杆菌数量(P0.05),显著提高28 d肉鸡回肠乳杆菌属数量(P0.05)。综上所述,日粮中添加发酵乳杆菌或凝结芽孢杆菌均对感染肉鸡的肠道微生物具有调控作用;其中添加凝结芽孢杆菌有利于肠道绒毛发育,缓解肠道损伤,一定程度上提高了肉鸡的生长性能,而发酵乳杆菌没有缓解肠道损伤的作用。  相似文献   

2.
试验以产气荚膜梭菌感染肉仔鸡建立坏死性肠炎模型,研究发酵乳杆菌和凝结芽孢杆菌对感染肉鸡生长性能和肠道健康的影响。将336只1日龄爱拔益加肉仔鸡随机分成4个处理组,每个处理6个重复。4个处理组分别为对照组、感染组、感染＋LF组（日粮添加1×109 CFU/kg发酵乳杆菌）、感染＋BC组（日粮添加1×1010 CFU/kg凝结芽孢杆菌）。所有感染肉鸡在14~21 d经口接种A型产气荚膜梭菌。试验期为28 d。结果显示：与对照组相比,灌服产气荚膜梭菌显著降低22~28 d肉鸡的日均采食量（P<0.05）,显著增加28 d十二指肠和空肠损伤评分（P<0.05）,显著提高21 d肉鸡盲肠的产气荚膜梭菌和大肠杆菌数量,显著降低28 d回肠产气荚膜梭菌数量（P<0.05）。与感染组相比,日粮添加发酵乳杆菌显著提高21 d肉鸡回肠的乳杆菌属数量（P<0.05）,显著降低21 d盲肠大肠杆菌的数量（P<0.05）;日粮添加凝结芽孢杆菌显著降低28 d肉鸡十二指肠损伤评分（P<0.05）,显著降低21 d十二指肠隐窝深度（P<0.05）,显著提高21 d空肠绒毛高度与隐窝深度的比值（P<0.05）,显著降低21 d肉鸡回肠和盲肠的大肠杆菌数量（P<0.05）,显著提高28 d肉鸡回肠乳杆菌属数量（P<0.05）。综上所述,日粮中添加发酵乳杆菌或凝结芽孢杆菌均对感染肉鸡的肠道微生物具有调控作用;其中添加凝结芽孢杆菌有利于肠道绒毛发育,缓解肠道损伤,一定程度上提高了肉鸡的生长性能,而发酵乳杆菌没有缓解肠道损伤的作用。  相似文献   

3.
本试验旨在研究日粮添加凝结芽孢杆菌对肠炎沙门氏菌感染肉鸡生产性能和抗氧化功能的影响。选用312只1日龄科宝500肉鸡公雏,随机分成4个处理,每个处理6个重复,每个重复13只鸡。采用2×2因子完全随机设计,将肉鸡分为无肠炎沙门氏菌感染和肠炎沙门氏菌感染组,日粮中凝结芽孢杆菌水平分别为0、400mg/kg。试验分1~21日龄和21~42日龄2个阶段。结果表明:日粮添加凝结芽孢杆菌显著提高了14~21日龄肉鸡的体增重以及饲料增重比(P0.05);肠炎沙门氏菌感染显著升高了感染后1周血清MDA含量(P0.05),显著降低感染后15 d血清T-AOC活力和CAT活力(P0.05);日粮添加凝结芽孢杆菌极显著提高了沙门氏菌感染后1周血清T-SOD活力和NO含量(P0.01),显著提高了感染后15 d血清T-AOC活力(P0.01)和CAT活力(P0.05),极显著提高了感染后30 d血清T-SOD活力(P0.01),极显著降低了感染后30 d血清MDA含量(P0.01)。肠炎沙门氏菌感染可降低肉鸡抗氧化功能,日粮添加凝结芽孢杆菌能够通过提高肉鸡的抗氧化能力而缓解因肠炎沙门氏菌感染所造成的氧化应激。  相似文献   

4.
试验采用2×2因子设计,选取264只1日龄雌性科宝肉仔鸡,分为4个处理,分别为对照(CON)组、产气荚膜梭菌感染(CP)组、复方组和复方+产气荚膜梭菌感染(复方+CP)组。对照组和CP组饲喂基础饲粮,复方组和复方+CP组在基础饲粮中添加400 mg/kg复合植物活性成分,CP组和复方+CP组肉鸡于第17～23日龄连续经口接种A型产气荚膜梭菌新鲜悬浮液(1×10~8CFU/mL),每只鸡每天接种1 mL。试验期为30 d。结果显示,在0～16日龄和24～30日龄各组生长性能均无显著差异(P0.05)。在17～23日龄,产气荚膜梭菌感染显著降低肉鸡平均日增重(P0.05),且显著降低23日龄肉鸡十二指肠绒毛高度与隐窝深度的比值(V/C)和30日龄肉鸡回肠绒毛高度(P0.05)。添加复合植物活性成分显著提高了17～23日龄产气荚膜梭菌感染肉鸡平均日增重(P0.05)和30日龄空肠绒毛高度(P0.05),但降低了23日龄空肠隐窝深度(P0.05)。通过肠道基因表达分析发现,产气荚膜梭菌感染显著下调了23日龄肉鸡空肠和回肠Claudin-2和TFF-2的相对表达量(P0.05),上调了空肠Mucin-2和Mucin5ac的相对表达量(P0.05)。添加复合植物活性成分提高了空肠Mucin-2和Mucin5ac及回肠TFF-2和Mucin5ac的相对表达量(P0.05),但降低了回肠Claudin-2水平。此外,复合植物活性成分提高了产气荚膜梭菌感染肉鸡空肠Occludin和E-cadherin的相对表达量(P0.05)。综上所述,饲粮中添加复合植物活性成分可改善产气荚膜梭菌感染肉鸡生长性能和肠道形态结构,调控肠道屏障功能相关基因表达,缓解肉鸡肠道损伤。  相似文献   

5.
本试验旨在研究凝结芽孢杆菌对肉鸡生长性能、免疫器官指数、血清生化指标及肠道菌群的影响。选择健康的1日龄AV500肉鸡10 000只,随机分成2组,每组5个重复,每个重复1 000只鸡。对照组饲喂基础饲粮,试验组饲喂基础饲粮+300 mg/kg凝结芽孢杆菌制剂。试验期6周。结果表明:1)1~21日龄、22~42日龄试验组肉鸡死淘率显著低于对照组(P0.05),分别下降了61.7%、52.42%;22~42日龄,试验组肉鸡的平均日增重、平均日采食量均显著高于对照组(P0.05)。2)21日龄试验组肉鸡的脾脏指数、胸腺指数、法氏囊指数均显著高于对照组(P0.05),而肠道指数却显著低于对照组(P0.05)。42日龄试验组肉鸡的脾脏指数、胸腺指数均显著高于对照组(P0.05)。3)21和42日龄试验组肉鸡血清中的丙氨酸氨基转移酶、碱性磷酸酶活性及总蛋白、球蛋白含量均显著高于对照组(P0.05)。4)21和42日龄试验组肉鸡盲肠、回肠食糜中凝结芽孢杆菌数量均显著高于对照组(P0.05),大肠杆菌数量均显著低于对照组(P0.05)。由此可见,饲粮中添加凝结芽孢杆菌可抑制肉鸡肠道中大肠杆菌的生长,提高免疫器官指数,降低死淘率。  相似文献   

6.
文章旨在研究日粮中添加凝结芽孢杆菌培养物对肉鸡生长性能、免疫指标、消化酶活性、肠道形态的影响。试验选取900羽体重45g左右的1日龄罗斯308肉鸡,随机分为3组,每组分为3个重复,每个重复为100羽。Ⅰ组：基础无抗日粮;Ⅱ组：在Ⅰ组日粮中添加75mg/kg金霉素;Ⅲ组：在Ⅰ组日粮中添加凝结芽孢杆菌培养物1000g/t。试验为期38d。结果表明,（1）凝结芽孢杆菌培养物对大肠杆菌K88、K99、肠炎沙门氏菌、产气荚膜梭菌有良好的抑菌活性。（2）生长性能：与Ⅰ组相比,Ⅲ组死亡率显著降低（P <0.05）,平均日增重显著提高（P <0.05）。（3）免疫指标：与Ⅰ组相比,Ⅲ组血清IgA、IgM、IgG含量和ND抗体水平显著提高（P <0.05）,ND抗体离散度显著降低（P <0.05）,胸腺指数和法氏囊指数显著提高（P <0.05）。（4）消化酶活性：Ⅲ组肠道淀粉酶、脂肪酶、胰蛋白酶活性比Ⅰ组显著提高（P <0.05）。（5）肠道形态：与I组相比,Ⅲ组空肠绒毛高度显著提高（P <0.05）。由此可见,凝结芽孢杆菌培养物可通过增强免疫力,增加小肠绒毛高...  相似文献   

7.
本试验评估了枯草芽孢杆菌PB6替代恩拉霉素对肉鸡产气荚膜梭菌的控制效果,结果表明:与肉鸡日粮中添加恩拉霉素相比,枯草芽孢杆菌PB6对肉鸡生产性能的影响不显著,但可提高成活率;枯草芽孢杆菌PB6可显著减轻肉鸡产气荚膜梭菌的感染程度。由此可见,枯草芽孢杆菌PB6可完全替代肉鸡日粮中的抗生素。  相似文献   

8.
本试验旨在研究凝结芽孢杆菌对黄羽肉鸡生产性能、血清生化指标及抗氧化功能的影响。选取1日龄黄羽肉鸡360羽,随机分为4组(每组6个重复,每重复15羽):Ⅰ组(对照组)饲喂基础饲粮,Ⅱ、Ⅲ、Ⅳ组饲喂分别添加100、200、300 mg/kg凝结芽孢杆菌(活菌数为1×109CFU/g)的试验饲粮,试验期70 d。结果表明:与对照组相比,1)饲粮添加200 mg/kg凝结芽孢杆菌显著提高了全期肉鸡平均日增重、成活率和胸肌率(P<0.05),显著降低了全期料重比(P<0.05);2)饲粮添加200 mg/kg凝结芽孢杆菌显著或极显著提高了28、70日龄肉鸡血清碱性磷酸酶活性(P<0.05或P<0.01)、70日龄血清白蛋白和总蛋白含量(P<0.05),极显著降低了70日龄血清尿素氮含量(P<0.01);3)饲粮添加200 mg/kg凝结芽孢杆菌显著提高了肉鸡28、70日龄血清中总抗氧化能力、超氧化物歧化酶活性和70日龄血清过氧化氢酶活性(P<0.05),极显著或显著降低了28、70日龄血清丙二醛含量(P<0.01或P<0.05)。由此可见,结合生产性能、血清生化指标及抗氧化功能指标,1~70日龄黄羽肉鸡饲粮添加200 mg/kg(2×108CFU/kg)凝结芽孢杆菌效果最佳。  相似文献   

9.
凹凸棒石黏土对产气荚膜梭菌攻毒肉鸡的影响   总被引：2，自引：0，他引：2  
将384只1日龄AA肉鸡随机分为4组(每组6重复),分别为对照组和3个产气荚膜梭菌攻毒组,对照组饲喂基础日粮,3个攻毒组分别饲喂基础日粮(感染组),基础日粮中添加40mg/kg杆菌肽锌(抗生素组)和2%凹凸棒石黏土(凹土组)的试验日粮,在第14～16天用产气荚膜梭菌对试验组肉鸡进行攻毒;于攻毒后的第7天测定肉鸡生产性能,并于攻毒后7d和11d测定肉鸡免疫器官指数、血清生化指标及肠道黏膜分泌性免疫球蛋白A(SIgA)和免疫球蛋白G(IgG)的含量。结果表明:产气荚膜梭菌攻毒对肉鸡生产性能无显著影响;攻毒后7d,脾和胸腺指数下降(P>0.05),而添加抗生素和凹土则使其有一定的升高趋势(P>0.05);攻毒后7d,各组碱性磷酸酶(AKP)活性都有下降趋势(P>0.05),攻毒后11d,感染组AKP升高了5.47%(P>0.05),但抗生素和凹土使AKP活性有一定下降(P>0.05);攻毒后7d和11d,感染组血清SIgA含量升高(P>0.05),日粮中添加凹土使血清SIgA含量降低(P>0.05);攻毒后11d,凹土使血清IgG含量升高(P<0.01)。可见凹土对产气荚膜梭菌攻毒肉鸡的负面效应有一定缓解作用。  相似文献   

10.
试验旨在探究厚朴提取物对产气荚膜梭菌感染肉鸡生长性能、肠道组织形态和屏障功能的影响。将264只1日龄肉仔鸡随机分成4组，每组6个重复，每个重复11只。试验期为23 d。对照组和产气荚膜梭菌感染组饲喂基础饲粮，厚朴提取物组和厚朴提取物+产气荚膜梭菌感染组在基础饲粮中添加400 mg/kg厚朴提取物。于18～23日龄产气荚膜梭菌感染组和厚朴提取物+产气荚膜梭菌感染组口服接种A型产气荚膜梭菌悬浮液1 mL(1×108cfu/mL，每天1次)，对照组和厚朴提取物组肉鸡灌服等量的灭菌培养基。结果显示：产气荚膜梭菌感染造成肉鸡小肠黏膜损伤，提高了23日龄回肠损伤评分(P<0.05)和血清二胺氧化酶活力，并降低了十二指肠绒隐比(P<0.05)及肉鸡空肠sIgA含量(P<0.05)；而日粮中添加厚朴提取物有降低1～17日龄肉鸡平均日采食量的趋势(P=0.05)，降低了23日龄肉鸡空肠绒毛高度(P<0.05)，提高了肉鸡空肠sIgA含量(P<0.05)；产气荚膜梭菌感染下调了空肠occludin、claudin-2及回肠mucin5ac、occludi...  相似文献   

11.
Coccidiosis is an intestinal parasitic infection and one of the most prevalent and economically damaging diseases of chickens. Furthermore, coccidia‐induced mucogenesis promotes secondary colonization by Clostridium perfringens, a major pathogen of chickens that causes necrotic enteritis. Our previous work found that supernatant of a culture of Bacillus amyloliquefaciens strain TOA5001 (BA) inhibited the growth of C. perfringens on Gifu anaerobic broth medium. Accordingly, we evaluated the effectiveness of dietary BA administration in inhibiting C. perfringens colonization of the intestine in broilers that were experimentally infected with coccidia. Ten healthy broilers from a BA‐supplemented (2 × 105 colony‐forming units/g of feed) broiler group and 10 from a non‐treated group were challenged with Eimeria tenella and E. maxima (5000 oocysts of each species/chick) at 28 days old. At 36 days old, five chicks from each group were slaughtered, whereas the remaining five in each group were killed at 49 days old. Dietary BA administration into Eimeria‐challenged birds reduced coccidial symptoms such as intestinal lesions. It also modified the cecal microbiota through suppressing C. perfringens and E. coli colonization, and inducing domination of Faecalibacterium prausnitzii, the Lactobacillus group and unknown Lachnospiraceae genera by bacterial DNA‐based metagenome analyses. B. amyloliquefaciens TOA5001 supplementation suppressed the symptoms of coccidiosis by modulating cecal microbiota in Eimeria‐challenged broilers.  相似文献   

12.
Bacillus species are commonly used as probiotics in the poultry feed industry for preventing infectious diseases and improving productivity by altering gastrointestinal microbiota. The growth parameters of Bacillus subtilis for surfactin production in fermentation and the benefits of surfactin on broiler chickens remain unclear. In this study, we examined the growth parameters of B. subtilis in fermentation and evaluated the effects of surfactin from B. subtilis‐fermented products on Clostridium perfringens‐induced necrotic enteritis and growth performance in broilers. Results showed that the highest viable biomass of B. subtilis was observed at 10% molasses and 2% yeast supplementation during fermentation. The 4‐ and 6‐day fermented B. subtilis products were heat‐, acid‐ and bile‐resistant. Furthermore, the 4‐day fermented B. subtilis products with the highest surfactin concentration showed the maximal antimicrobial activity against pathogens, including Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and C. perfringens. Dietary B. subtilis‐fermented product supplementation in broilers significantly improved intestinal morphology and necrotic lesions under C. perfringens challenge. Bacillus subtilis treatments could enhance broiler productivity, as well as promote bone quality and intestinal morphology. These results together indicate that B. subtilis‐fermented products containing surfactin have potential for the development as feed additives and use as possible substitutes for antibiotics to treat C. perfringens in the poultry industry.  相似文献   

13.
本试验旨在研究发酵床饲养模式下日粮中添加地衣芽孢杆菌对仔猪生长性能、胰腺和小肠黏膜消化酶活性及肠道主要菌群数量的影响。选用108头体重13kg左右的35日龄健康苏钟猪,随机分为3组,每组3个重复,每个重复12头,分别饲喂基础日粮(对照组)、基础日粮+40mg/kg杆菌肽锌+20mg/kg硫酸黏杆菌素(抗生素组)、基础日粮+300mg/kg地衣芽孢杆菌(益生菌组)的试验日粮。预试期7d,正试期52d。结果表明:1与对照组相比,日粮中添加地衣芽孢杆菌能够在一定程度上提高仔猪平均日增重、平均日采食量,降低料重比,但各组间差异均不显著(P0.05)。2与对照组相比,日粮中添加地衣芽孢杆菌能够极显著提高仔猪胰腺中淀粉酶活性、十二指肠黏膜中麦芽糖酶活性和空肠黏膜中乳糖酶活性(P0.01),十二指肠黏膜和空肠黏膜中蔗糖酶活性显著提高(P0.05)。3与对照组相比,日粮中添加地衣芽孢杆菌能够显著提高仔猪盲肠芽孢杆菌数量(P0.05);乳酸杆菌数量较对照组提高4.09%,大肠杆菌数量较对照组降低4.86%,但均未达到显著水平(P0.05)。综上所述,在本试验条件下,日粮中添加300mg/kg地衣芽孢杆菌能够提高发酵床饲养仔猪胰腺、小肠黏膜消化酶活性及盲肠芽孢杆菌数量,同时仔猪生长性能也在一定程度上有所改善。  相似文献   

14.
Anise oil (AO) is a phytochemical with antibiotic properties and it reduces the growth of Clostridium perfringens in vitro, which is the main causal agent of necrotic enteritis. A series of battery experiments was conducted to determine an AO dosage to feed to broilers and its effect during 2 C. perfringens challenges, and a floor pen experiment to determine its effect in performance. Anise oil linearly reduced (P < 0.05) ADFI and ADG, but feeding broilers 500 to 2,000 mg/kg of AO resulted in similar performance with positive control (PC) fed broilers. Broilers were challenged on d 10 (Experiment 2) or on d 10 and 13 (Experiment 3). Broilers fed AO had lower (P < 0.05) ADFI and ADG compared with broilers fed PC from zero to 18 d (Experiment 2). Growth performance of broilers fed AO was not affected (P > 0.05) during Experiment 3. In both challenges, the jejunum of broilers fed AO had fewer and milder (P < 0.05) lesions compared with broilers fed PC or negative control (NC) diets. In a floor pen trial, 1,000 mg/kg of AO was fed to broilers from zero to 42 days. Broilers fed AO or PC had similar (P > 0.10) growth performance for the entire trial. Broilers fed PC or AO had greater ADG (P < 0.05) and tended (P = 0.07) to be heavier than broilers fed NC at the end of the trial. Breast yield percentage was similar (P > 0.10) among broilers fed any of the dietary treatments. Residues of AO were not present at detectable levels in breast meat.  相似文献   

15.
Since the ban on growth-promoting antibiotics in animal feed in the European Union, necrotic enteritis has become a major cause of mortality in broiler chickens. Despite the importance of the disease, the pathogenesis is still not completely understood. In the current study, Clostridium perfringens strains isolated from healthy flocks and isolates from outbreaks of necrotic enteritis were evaluated for the ability to cause gut necrosis in an intestinal loop model in laying hens and in an experimental infection model in broilers. High, intermediate and low alpha toxin producing strains were chosen from each isolation source. Only the isolates from field outbreaks induced necrotic gut lesions, independent of the amount of alpha toxin produced in vitro. It was also shown that alpha toxin producing isolates from calf hemorrhagic enteritis cases were not able to induce necrotic enteritis in poultry. These results suggest the presence of host specific virulence factors in C. perfringens strains, isolated from chickens with intestinal necrotic enteritis lesions.  相似文献   

16.
试验旨在研究肉鸡日粮中添加枯草芽孢杆菌B7对其生长性能及免疫功能的影响。将200只1日龄健康爱拔益加肉雏鸡随机分成5组,每组4个重复,每个重复10只。对照组饲喂基础日粮,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别在基础日粮中添加2×105、5×105、8×105和1×106 CFU/g枯草芽孢杆菌B7。试验期42 d。结果表明:①在整个试验阶段,除29～35日龄外,试验Ⅱ组肉鸡的日增重均高于对照组,料重比均低于对照组;36～42日龄时,与对照组相比,试验Ⅱ组肉鸡的日增重显著提高了10.25%(P<0.05),料重比显著降低了14.83%(P<0.05)。②28日龄时,试验Ⅱ组脾脏指数高于对照组31.96%,差异显著(P<0.05);除14和28日龄外,试验Ⅱ组法氏囊指数均显著高于对照组(P<0.05);试验Ⅱ组新城疫抗体效价处于较高水平,28和35日龄时,试验Ⅱ组新城疫抗体效价分别高于对照组16.04%和18.09%,差异显著(P<0.05);21、35和42日龄时,试验Ⅱ组血清中IgG含量分别高于对照组81.94%、46.67%和15.63%,差异显著(P<0.05)。由此可知,添加5×105 CFU/g枯草芽孢杆菌B7能够提高肉鸡的生长性能,增强肉鸡的免疫功能,综合比较,试验Ⅱ组的5×105 CFU/g为枯草芽孢杆菌B7的最佳添加量。  相似文献   

17.
The present study investigates, under field conditions, the influence of antimicrobial administration on prevalence and patterns of antimicrobial resistance among Escherichia coli and Enterococcus spp. isolated from growing broilers. For this purpose, a group of 16,000 commercial broiler chickens was treated with enrofloxacin from day 1 to day 3, gentamicin from day 19 to day 21, and ampicillin from day 26 to day 28. A control group of 16,000 broilers was placed in the same controlled environment poultry house. Fecal (from both groups) and feed samples were collected at regular intervals. Few E. coli isolates were obtained from either farm environment or poultry feed samples, while enterococci were found to be ubiquitous among these samples. The frequency of resistance against most antimicrobials tested was significantly higher (P < 0.05) in E. coli isolated from broilers receiving intermittent antimicrobial pressure than that from non-medicated broilers, whereas in enterococci these differences were only observed among structurally related antimicrobial drugs and over a short period of time. By the time the broilers reached market age (33 days), several multi-resistant E. coli and enterococci were detected in the feces of the medicated group. Results suggest that antimicrobial resistance in E. coli was mainly medication-dependent, whereas among enterococci, changes observed over time were apparently influenced by factors apart from antimicrobial exposure, namely the resistance organisms previously present in farm environment and those present in feedstuffs.  相似文献   

18.
The anaerobic mastitis incidence was used to study the bovine udder response in anaerobic bacterial mastitis caused by the Gram-positive bacterial strain of Clostridium perfringens. Milk samples positive for C. perfringens were assayed for NO and lysozyme. The model produced a strong NO and lysozyme response which correlated positively with the severity and outcome of the disease (subclinical and clinical stages). This study is, to our knowledge, the first to suggest a possible link between NO and lysozyme and bovine mastitis caused by C. perfringens. The results raise the possibility that interfering with NO production during mastitis may help to prevent tissue damage.  相似文献   

19.
Clostridium-related poultry diseases such as necrotic enteritis (NE) and gangrenous dermatitis (GD) cause substantial economic losses on a global scale. Two antigenic Clostridium perfringens proteins, elongation factor Tu (EF-Tu) and pyruvate:ferredoxin oxidoreductase (PFO), were identified by reaction with immune sera from commercial meat-type chickens with clinical outbreak of Clostridium infections. In addition to the genes encoding EF-Tu and PFO, C. perfringens alpha-toxin and necrotic enteritis B-like (NetB) toxin were also expressed in Escherichia coli and their corresponding recombinant proteins were purified. Using the four recombinant proteins as target antigens in ELISA immunoassays, high serum antibody titers were observed not only in chickens with clinical signs of Clostridium infections, but also in apparently healthy animals from the same disease-endemic farm. By contrast, no antibodies against any of the proteins were present in the serum of a specific pathogen-free bird. In ELISA using recombinant proteins of C. perfringens, the levels of anti-bacterial protein antibodies were also higher in chickens which were experimentally induced to show NE clinical signs after co-infection with C. perfringens and Eimeria maxima compared with uninfected controls. These results show that two antigenic C. perfringens proteins, EF-Tu and PFO can be useful detection antigens for C. perfringens-afflicted infections in commercial poultry.  相似文献   

20.
本试验旨在研究低蛋白质饲粮添加载锌蒙脱石(Zn-MMT)对肉鸡生长性能、免疫器官发育和肠道组织形态的影响。随机选择1日龄健康科宝公雏288只,按体重一致原则随机分成6个组,每组6个重复,每个重复8只鸡。对照组饲喂玉米-豆粕型低蛋白质基础饲粮,正对照组[硫酸锌(ZnSO 4)组]饲喂低蛋白质基础饲粮+40 mg/kg ZnSO 4,4个试验组分别在低蛋白质基础饲粮中添加20、40、60和80 mg/kg Zn-MMT(均以锌含量计算)。试验鸡自由采食和饮水,试验期为42 d。结果表明:1)与对照组和ZnSO 4组相比,低蛋白质饲粮添加60和80 mg/kg Zn-MMT显著降低肉鸡1~21日龄平均日增重(ADG,P<0.05),添加80 mg/kg Zn-MMT显著提高肉鸡1~21日龄料重比(F/G,P<0.05);添加Zn-MMT对肉鸡22~42日龄和1~42日龄ADG、平均日采食量和F/G以及1~21日龄ADG无显著影响(P>0.05)。2)与对照组相比,低蛋白质饲粮添加Zn-MMT对肉鸡21和42日龄免疫器官指数无显著影响(P>0.05);但与ZnSO 4组相比,低蛋白质饲粮添加Zn-MMT显著提高肉鸡21日龄胸腺指数和法氏囊指数(P<0.05),且添加80 mg/kg Zn-MMT显著提高肉鸡42日龄胸腺指数(P<0.05)。3)与对照组相比,低蛋白质饲粮添加20和60 mg/kg Zn-MMT显著提高肉鸡42日龄腿比率(P<0.05);与ZnSO 4组相比,低蛋白质饲粮添加Zn-MMT对肉鸡屠宰性能无显著影响(P>0.05)。4)与对照组相比,低蛋白质饲粮添加40和60 mg/kg Zn-MMT显著降低肉鸡十二指肠隐窝深度(CD,P<0.05),且添加60 mg/kg Zn-MMT显著降低肉鸡空肠CD(P<0.05);添加20 mg/kg Zn-MMT显著降低肉鸡回肠CD(P<0.05),并显著提高肉鸡回肠绒毛高度(VH)/CD(V/C)值(P<0.05);同时,添加80 mg/kg Zn-MMT显著降低肉鸡空肠V/C值(P<0.05)。与ZnSO 4组相比,低蛋白质饲粮添加20 mg/kg Zn-MMT显著提高肉鸡回肠V/C值(P<0.05),并显著降低回肠CD(P<0.05);添加40 mg/kg Zn-MMT显著提高肉鸡空肠VH(P<0.05),并显著降低肉鸡十二指肠CD(P<0.05);添加20和60 mg/kg Zn-MMT显著降低肉鸡空肠CD(P<0.05);添加20、40和60 mg/kg Zn-MMT显著提高肉鸡空肠V/C值(P<0.05)。综上所述,在低蛋白质饲粮中添加Zn-MMT对肉鸡后期生长性能无显著影响,但与添加ZnSO 4相比,可显著提高肉鸡免疫器官指数,提高小肠VH和V/C值,降低小肠CD,促进肉鸡肠道发育。  相似文献   

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