Organic acid blends improve intestinal integrity,modulate short-chain fatty acids profiles and alter microbiota of broilers under necrotic enteritis challenge     

Alip Kumar  Mehdi Toghyani  Sarbast K.Kheravii  Lane Pineda  Yanming Han  Robert A.Swick  Shu-Biao Wu 《动物营养（英文）》2022,8(1):82

Controlling enteric diseases of broilers is crucial.Among many additives,organic acids(OA)and their blends are gaining attention to combat diseases in the post-antibiotic era.The current study evaluated the potentials of short-chain fatty acids(SCFA)and medium-chain fatty acids(MCFA)blends and/or phenolic compounds on intestinal integrity,intestinal pH,caecal microbiota,and caecal SCFA profiles of broilers under necrotic enteritis(NE)challenge.The additives used were:(A)a blend of SCFA,MCFA,and a phenolic compound(SMP),(B)a blend of free and buffered SCFA with MCFA(SMF),and(C)a blend of free and buffered SCFA with a high concentration of MCFA(SHM).A total of 1,404 male parental chicks of Ross 308 broilers were randomly allocated to 78 floor pens on hatching day with 6 treatments replicated 13 times with 18 birds per pen.The treatments were:UCC,unchallenged control;CHC,challenged control;BAC,challenged group plus zinc bacitracin;SMP,challenged group plus additive SMP;SMF,challenged group plus additive SMF;SHM,challenged group plus additive SHM.Birds were challenged with field-strain Eimeria spp.on d 9 and Clostridium perfringens on d 14.Birds challenged with NE increased fluorescein isothiocyanate dextran(FITC-d)concentration in serum,reduced acetate and butyrate concentrations,and increased Bacteroides and C.perfringens load in the caeca(P<0.05).Birds fed additives decreased FITC-d from gut to serum,reduced Bacteroides(d 16,P<0.05)and numerically reduced C.perfringens load compared to CHC group.Birds fed additive SHM had higher concentrations of acetate and butyrate(d 21,P<0.05)than CHC group but were not different from SMP and SMF groups.All the additives exhibited similar intestinal protection against NE compared to the BAC group indicated by FITC-d concentration in serum,acetate,propionate and butyrate concentrations in the caeca,and caecal bacterial loads except for the C.perfringens(P>0.05).The SMP group had a higher load compared to BAC(P<0.05).These findings suggest the promising effects of OA blends as alternatives to BAC to ameliorate the impact of NE challenge of broilers as indicated by improved intestinal health.  相似文献   

Flounder with partial intestine osmoregulate in seawater     

J.L. Specker  K. Sundell  M. Chandlee  B. Soffientino 《Fish physiology and biochemistry》2000,23(2):159-164

Summer flounder (Paralichthys dentatus) that survived flounder infectious necrotizing enteritis (FINE) provided an unusual model for testing the role of the intestine in maintaining salt and water balance. The survivors lost 67% of the posterior-most intestine. The remaining stump of the anterior intestine healed and became a blind pouch. We sampled the fish three months after the epizootic ended, demonstrating that these fish survive with only a portion of their intestine. We hypothesized that salt and water balance would be disturbed in the survivors of FINE. However, plasma osmolality and concentrations of Na⁺, Cl^–, and K⁺ were the same in intact flounder and those with only an intestinal stump. No compensatory changes in gill Na⁺, K⁺-ATPase activity were detected. The fish with intestinal stumps continued to feed, but their body weight was only 41% that of intact fish. Summer flounder can maintain salt and water homeostasis, but fail to thrive, using only one-third of their intestine.  相似文献   

重组鸭瘟病毒载体中筛选高效表达鸭坦布苏病毒E蛋白启动子   总被引：1，自引：0，他引：1  

陈柳  倪征  余斌  华炯钢  叶伟成  云涛  刘可姝  朱寅初  张存 《中国农业科学》2020,53(24):5125-5134

【背景】鸭瘟和鸭坦布苏病毒是鸭的两种重要传染病,鸭瘟属于疱疹病毒科,具有开发成病毒载体的优势。为了优化鸭坦布苏病毒E基因在重组鸭瘟病毒载体中的表达,之前探讨了不同形式鸭坦布苏病毒E蛋白在重组鸭瘟病毒载体中的表达,发现以鸭为宿主进行密码子优化的E基因C端截短形式（E451-dk,简称为Es）表达量最高。【目的】探讨不同启动子对Es 在重组鸭瘟病毒载体中表达的影响,为鸭瘟病毒—坦布苏病毒二联苗的研制奠定基础。【方法】将pCAG、 pSV40、pRSV、p1.8k(MDV)和pgB(MDV)启动子通过常规基因克隆的方法替换转移载体pEP-BGH-Es中的pCMV启动子,构建不同启动子调控Es表达的重组表达框pro-Es-BGH-pA。在鸭瘟病毒（DEV）疫苗株细菌人工染色体克隆pDEV-EF1的基础上,将5个重组表达框分别通过“Red E/T两步重组”克隆至pDEV-EF1突变体的US7和US8基因之间,构建了携带不同启动子调控的Es突变体克隆pDEV-pro-Es。用磷酸钙法转染鸡胚成纤维细胞（CEFs）拯救获得相应重组病毒rDEV-pro-Es,并对重组病毒感染细胞蚀斑大小和Es蛋白表达情况进行测定。【结果】将重组突变体克隆转染细胞拯救获得了5株重组病毒rDEV-pro-Es。Western blotting分析表明外源蛋白Es在 pRSV调控下表达量最高,其表达量较rDEV-Es提高了169.12%。【结论】完成了Es在重组鸭瘟病毒载体中高效表达启动子的筛选,获得了一种调控Es高效表达的启动子pRSV。同时也获得了一株高效表达鸭坦布苏病毒外源基因Es的重组鸭瘟病毒rDEV-pRSV-Es。  相似文献   

鸭肠炎病毒UL41、UL42基因的克隆与分析     

陈普成  柳金雄  曾青华  姜永萍  田国彬  陈化兰 《中国预防兽医学报》2009,31(12)

依据GenBank登录的鸭肠炎病毒(DEV)核苷酸序列设计引物,利用长片段PCR技术扩增了DEV基因组UL36与UL43基因之间的未知序列,扩增所得片段长度约为15 kb.经EcoRV单酶切,将其中的3.9 kb片段克隆到pUC18中.序列分析表明该3.9 kb EcoR V片段含有2个完整的转录方向相反的与单纯疱疹病毒(HSV)UL41和UL42基因同源的ORF,命名为DEV UL41和ULA2基因.通过氨基酸序列比对发现:DEV UL41基因含有5个高度保守位点,而UL42含有2个,进化树分析表明DEV与疱疹病毒科a疱疹病毒亚科的马立克病毒、火鸡疱疹病毒的进化关系非常相近,为DEV的分类提供了参考依据.  相似文献   

DuCV和GPV与DEV三重PCR检测方法的建立及应用     

田琴  张明华  周碧君  程振涛  王开功  文明 《湖南农业大学学报(自然科学版)》2021,47(2):225-230

根据GenBank中的序列,合成针对鸭圆环病毒(DuCV)REP基因、鹅细小病毒(GPV)NS1基因、鸭肠炎病毒(DEV)UL6基因的3对特异性引物,以病毒的克隆质粒作为模板,进行退火温度、引物终浓度的优化,建立一种能同时鉴别DuCV、GPV、DEV的三重PCR检测方法,并检验该方法的特异性、敏感性和重复性.结果显示:...  相似文献   

雏鹅新型病毒性肠炎病毒的提纯和核酸链型及结构蛋白分析   总被引：6，自引：0，他引：6  

汪铭书  程安春  周毅  陈孝跃 《畜牧兽医学报》2002,33(3):276-279

本文报道雏鹅新型病毒性肠炎病毒（NGVEV）的提纯方法、核酸类型及结构蛋白分析的研究结果。采用氯仿处理－饱和硫酸铵沉淀－透析清除NH4^ 、SO4^2-柱层析分离的技术程序可获得纯将的NGVEV病毒粒子。于电镜下可观察到NGVEV具有典型的腺病毒特征。经吖啶橙染色和S1核酸酶消化鉴定NEVEV的核酸类型为双链DNA。经SDS－PAGE分析，病毒结构蛋白由15种多肽组成，即VP1（116KD）、VP2（104KD）、VP3（88KD）、VP4（68KD）、VP5（60.7KD）、VP6（54KD）、VP7（40.1KD）、VP8（36KD）、VP9（34.5KD）、VP10（24.2KD）、VP11（22KD）、VP12（20KD）、VP13（18KD）、VP14（14.2KD）和VP15（13.4KD)。其中VP4、VP7、VP8、VP9、VP14为主要结构多肽，占蛋白总量的90.2622%。  相似文献   

"三黄汤"合剂治疗仔猪白痢病的效果观察   总被引：1，自引：0，他引：1  

王会香  戴扬川  袁天旭 《四川畜牧兽医》2000,27(6):27-27

利用中药“三黄汤”治疗仔猪白痢,达到清热解毒,抗菌消炎,收敛,止痢的效果。  相似文献   

Evaluation of the Presence and Level of Enramycin in Broiler Tissues Following In-Feed Administration at Therapeutic Dose     

《The Journal of Applied Poultry Research》2018,27(4):449-452

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The effect of hen-egg antibodies on Clostridium perfringens colonization in the gastrointestinal tract of broiler chickens     

Wilkie DC  Van Kessel AG  Dumonceaux TJ  Drew MD 《Preventive veterinary medicine》2006,74(4):279-292

We evaluated the ability of hen-egg antibodies (HEA) to reduce intestinal colonization by Clostridium perfringens in broiler chickens. Antibodies against C. perfringens or cholera toxin (negative control) were obtained from the eggs of laying hens hyperimmunized using a C. perfringens bacterin or cholera toxin. Eggs were collected, pooled, and egg antibodies were concentrated by polyethylene-glycol precipitation. An initial experiment was conducted to determine the in vivo activity of the administered antibody along the length of the intestine. Thereafter, two feeding trials were performed to assess the efficacy of feed amended with the egg antibodies in reducing the level of colonization of C. perfringens in challenged birds. Antibody activity declined from proximal to distal regions of the intestine but remained detectable in the cecum. In the first experiment there was no significant reduction in the number of C. perfringens in the birds fed the diet amended with the anti-C. perfringens egg antibody, compared to the birds that received the anti-cholera toxin egg antibody (n = 10), at any of the sampling times. In the second experiment there was a significant decrease in C. perfringens intestinal populations 72 h after treatment (n = 15) as assessed by culture-based enumeration, but there was no decrease as measured by quantitative PCR based on the C. perfringens phospholipase C gene. Intestinal-lesion scores were higher in the birds that received the anti-C. perfringens HEA. Our work suggests that administration of HEA did not reduce the level of C. perfringens intestinal colonization and conversely might exacerbate necrotic enteritis.  相似文献   

水貂肠炎病毒VP2基因的原核表达及鉴定     

钱毓斌  张彦龙 《野生动物》2012,33(3):118-121

在分析水貂肠炎病毒VP2基因主要抗原位点分布的基础上,设计了1对特异性引物,克隆一段长为846 bp,编码主要抗原位点的基因片段。将该基因片段定向插入表达载体PET-32a中,转化BL21(DE3)菌株,IPTG诱导实现高效表达。诱导表达比较实验结果表明,在37℃,IPTG浓度为1.0 mM,诱导时间为6 h,诱导表达达到最大效率。重组蛋白以包涵体形式存在,大小约为50 KD,应用兔抗水貂MEV抗体,经Western-blotting验证该重组蛋白具有MEV的抗原性,可为今后抗MEV单克隆抗体制备及相关免疫学检测方法的建立提供良好的抗原物质。  相似文献