谷氨酰胺对肉鸡小肠组织结构和吸收能力的影响

本试验旨在研究饲粮不同添加水平谷氨酰胺(Gln)对热应激肉鸡小肠组织结构和吸收能力的影响.选用1日龄科宝- 500肉鸡240只,随机分为6个处理,每个处理4个重复,每个重复10只.Ⅰ组为对照组,饲喂玉米-豆粕型基础饲粮,Ⅱ、Ⅲ、Ⅳ、Ⅴ和Ⅵ组为试验组,分别饲喂在基础饲粮中添加0.4％、0.8％、1.2％、1.6％和2.0...     

枯草芽孢杆菌对肉鸡小肠黏膜组织形态结构的影响

本试验旨在探讨枯草芽孢杆菌对肉鸡小肠形态参数的影响,为枯草芽孢杆菌在肉鸡生产中的应用提供参考依据。试验选取200羽1日龄健康的AA肉鸡,随机分为4组,每组5个重复,每个重复10羽。A组(对照组)饲喂基础日粮,B、C、D组为试验组,分别在基础日粮中添加0.05%、0.10%、0.15%的枯草芽孢杆菌制剂(活菌数为10~(10)CFU/g)。试验期为42 d。试验结果显示:(1)各试验组小肠的黏膜结构都比对照组完整;(2)各试验组的小肠各段绒毛高度、绒毛高度与隐窝深度比值(the Ratio of Villus Height to Crypt Depth,V/C值)、黏膜厚度及肌层厚度均高于对照组;(3)对照组V/C值由十二指肠向回肠逐渐减小,而各试验组V/C值,十二指肠的最大,其次是空肠,回肠的最小。以上结果表明:添加剂枯草芽孢杆菌均可不同程度地改善肉鸡小肠的黏膜结构,并且枯草芽孢杆菌添加量为0.15%时效果较好。     

有机铬对肉鸡日粮、粪中微量元素和小肠组织结构的影响

试验选用1日龄爱拔益加(AA)肉鸡792只,设6个处理,每个处理4个重复,每个重复33只鸡。对照组饲喂玉米-豆粕型基础日粮,试验组分别饲喂在基础日粮中添加酵母铬0.2 mg/kg、吡啶甲酸铬0.2 mg/kg和蛋氨酸铬0.1 mg/kg(Ⅰ)、0.2 mg/kg(Ⅱ)、0.6 mg/kg(Ⅲ)的日粮(以Cr3+计),自由采食、饮水,试验期为49 d。旨在研究日粮中添加不同有机铬源对肉鸡日粮、粪中微量元素和小肠组织结构的影响。结果表明,(1)酵母铬组和吡啶甲酸铬组日粮铜水平均显著降低(P<0.05),蛋氨酸铬(Ⅱ)组日粮锌水平显著降低(P<0.05);吡啶甲酸铬组和蛋氨酸铬(Ⅱ)组粪铜、粪锌排泄量均显著提高(P<0.05),且蛋氨酸铬(Ⅱ)组粪锰水平显著增加(P<0.05);不同铬源对日粮铁水平和粪铁排泄量均未产生显著影响(P>0.05)。(2)不同铬源均增加空肠黏膜厚度的趋势,且蛋氨酸铬(Ⅲ)组较对照组显著提高28.57%(P<0.05);不同铬源均能降低回肠绒毛长度和黏膜厚度,除酵母铬组黏膜厚度外,其他各试验组均达到显著水平(P<0.05);各试验组十二指肠绒毛长度和黏膜厚度差异均不显著(P>0.05)。由此可见,铬对日粮和粪中铜、锌、锰水平影响显著,对铁影响不显著;能增加空肠黏膜厚度,显著降低回肠绒毛长度和黏膜厚度。     

3种饲料添加剂对肉鸡小肠形态结构的影响

将32只1日龄健康AA肉鸡随机分为4个处理组：A组（对照组，基础日粮）、B组（抗生素组，基础日粮＋硫酸抗敌素100mg／kg）、C组（中草药组，基础日粮＋幼康宝500mg／kg）和D组（丁酸钠组，基础日粮＋丁酸钠500mg／kg）。试验7周后，采用组织学技术研究肉鸡小肠黏膜结构的形态及其变化。结果显示：（1）各试验组小肠的黏膜结构都比对照组完整；（2）各试验组的小肠各段绒毛高度、V／C值、黏膜厚度及肌层厚度均高于对照组；（3）对照组V／C值由十二指肠向回肠逐渐降低，而各试验组V／C值，十二指肠的最大，回肠的次之，空肠的最小。结论：3种添加剂均可不同程度地改善肉鸡小肠黏膜结构，并且丁酸钠和幼康宝在一定程度上具有替代硫酸抗敌素的可行性。     

蜂花粉对肉鸡小肠发育的影响

将144只1日龄AA肉鸡随机分为2组，每组72只，日粮中分别添加0(对照组)和15g／kg(试验组)的蜂花粉，每周每组随机抽取试验鸡6只，剖取十二指肠、空肠、回肠，测量肠管长度及肠绒毛、肠腺长度，并制作石蜡切片，进行组织学观察，研究了日粮中添加蜂花粉对肉鸡小肠发育的影响。结果显示，试验组1～3周龄鸡的小肠绒毛和肠腺的长度显著或极显著高于对照组，肠道淋巴组织较发达，证实蜂花粉能够促进肉鸡小肠的早期发育，增强组织免疫功能。     

溶菌酶和抗生素对肉鸡组织IGF-Ⅰ mRNA的影响

选择144只1日龄艾维因肉鸡分为4组,对照组饲喂基础日粮,抗生素组饲喂添加抗生素(有效成分为杆菌肽锌和硫酸粘杆菌素)的基础日粮,2个溶菌酶组分别饲喂基础日粮添加溶菌酶150mg/kg和300mg/kg的日粮,每组6个重复,每个重复6只,于42日龄取样,采用RT-PCR方法测定肉鸡肝脏和胸肌IGF-ⅠmRNA的相对表达水平。试验结果表明:溶菌酶组较对照组可将肝脏IGF-ⅠmRNA水平分别提高12.5%和10.4%,但与对照组及抗生素组相比差异不显著(P0.05);各处理对胸肌IGF-ⅠmRNA水平有提高的趋势,但无显著差异(P0.05)。     

复合生物制剂替代部分抗生素对肉鸡生产性能和小肠形态的影响

本试验旨在研究2种复合生物制剂替代部分抗生素对肉鸡生产性能和小肠黏膜组织形态等指标的影响。选用12栋商品代爱拔益加肉鸡,随机分成对照组、试验1组和试验2组共3个处理组,每个处理组设4个重复,每重复为1栋鸡舍,每栋鸡舍10 000只肉鸡。结果表明,复合生物制剂在替代部分抗生素后,能够促进肉鸡小肠绒毛的生长、隐窝变浅,提高了绒毛长度与隐窝深度的比值,使肉鸡肠道更健康,有利于小肠营养物质的吸收,从而改善了肉鸡出栏重、料肉比等生产性能。     

安普霉素对仔猪肠道微生物及肠壁组织结构的影响

采用单因子试验设计,72头28日龄大长北三元杂交断奶仔猪随机分为3组,以研究饲料中添加不同剂量的安普霉素(0、20、90mg/kg)对仔猪肠道中大肠杆菌、双歧杆菌和乳酸杆菌的增殖及其肠壁组织结构的影响。试验期为4周。研究结果表明:(1)90mg/kg安普霉素能明显降低仔猪腹泻发生率,对仔猪具有显著促生长作用,可提高断奶后0～4周内仔猪日增重19 1%～24 6%(P<0 05)、改善饲料转化率7 7%～8 5%(P<0 05),并可提高日采食量8 4%～13 1%。尤其在试验前期(断奶后0～2周)作用更明显。(2)饲料中添加90mg/kg安普霉素对断奶后0～2周、3～4周仔猪肠道(空肠、盲肠和结肠)中大肠杆菌的增殖均有明显抑制作用(P<0 05),可分别降低10 7%～18 1%、9 1%～14 0%,且前期的作用效果更明显;同时,也可显著降低0～2周空肠内乳酸杆菌的数量(P<0 05),一定程度上抑制空肠内双歧杆菌的增殖,减弱空肠内微生物的代谢活动,显著降低仔猪空肠内乙酸、丁酸和总挥发性脂肪酸的产生量(P<0 05),从而可减少与机体竞争营养、降低肠内有害代谢物水平。(3)在仔猪日粮中添加90mg/kg的安普霉素可显著减轻小肠相对重量17 7%(P<0 05)、缩短小肠相对长度13 7%(P<0 05),并使小肠绒毛排列规则、高度增加(P<0 05),绒毛高度/隐窝深度的比值增大,说明安普霉素对仔猪具     

那西肽对仔猪肠道微生物及肠壁组织结构的影响

采用单因子试验设计,36头二元杂交(大白×长白)断奶仔猪随机分为4组,每组9头,每个重复3头,以研究饲料中添加5,10,20mg/kg的那西肽(低、中、高剂量)对仔猪肠道中大肠杆菌、双歧杆菌和产气荚膜梭菌的增殖及其肠壁组织结构的影响。结果表明:高剂量组能明显降低仔猪腹泻发生率,对仔猪具有促生长作用。饲粮中添加那西肽后,在仔猪空肠部分均有降低肠壁厚度、肠隐窝深度和增加肠绒毛高度的作用趋势,与对照组相比,差异均不显著。在仔猪回肠部分,高剂量那西肽组的肠壁厚度与对照组相比显著降低了24.31%(P<0.05);高剂量组的肠绒毛高度与对照组相比,差异显著(P<0.05);但对肠隐窝深度没有显著影响(P>0.05)。饲粮中添加那西肽后,在仔猪的空肠、回肠和结肠中均出现增加大肠杆菌数量、降低双歧杆菌和产气荚膜梭菌数量的趋势。随着那西肽添加剂量的增加,作用效果越显著。     

运输应激对AA肉鸡组织结构的影响

集约化养殖的畜禽进出养殖场和屠宰前都必须经过运输,运输过程中由于捕捉、挤压、断水、断食、噪音及过度疲劳等原因所造成的运输应激会导致动物的生理、心理状态和代谢过程发生相应地变化,严重时甚至会死亡,给畜牧业生产带来巨大损失。本试验利用组织学及病理学方法研究了不同的运输时间对AA肉鸡不同组织造成的影响。选取生长状况相似健康的7周龄AA肉鸡40只,随机分成4组,每组10只,分别运输2h、3h、4h和5h,结束后立即剖杀,取心、肝、脾、肺、肾、胸腺等不同组织置于10%甲醛中,H-E染色光学显微镜下观察并拍照。结果表明:运输应激初期(2h)多数组织出现毛细血管扩张充血、细胞肿胀等急性病理性变化。运输3h到4h各组织的病理改变与初期相似但有所加重,运输5h心脏出现了心肌纤维的断裂,胸腺、脾、肾出现了功能衰竭等现象。由此可见,运输应激可导致组织细胞应激性损伤,并且组织损伤的程度随着运输时间的延长而有所波动。     

Effect of addition of a probiotic micro‐organism to broiler diet on intestinal mucosal architecture and electrophysiological parameters

Probiotics might be one of the solutions to reduce the effects of the recent ban on antimicrobial growth promoters in feed. However, the mode of action of probiotics still not fully understood. Therefore, evaluating probiotics (microbial feed additives) is essential. Thus the objective of this work was to investigate the efficacy of a new microbial feed additive (Lactobacillus salivarius and Lactobacillus reuteri) in broiler nutrition. The body weight (BW), average daily weight gain was relatively increased by the dietary inclusion of Lactobacillus sp. in broiler diets. Furthermore, the Lactobacillus feed additive influenced the histomorphological measurements of small intestinal villi. The addition of Lactobacillus sp. increased (p < 0.05) the villus height (VH)/crypt depth ratio and the VH was numerically increased in duodenum. The duodenal crypt depth remained unaffected (p > 0.05), while the ileal crypt depth was decreased by dietary supplementation of Lactobacillus sp. compared with the control. At the end of the feeding period, the basal and glucose stimulated short‐circuit current (Isc) and electrical tissue conductivity were measured in the isolated gut mucosa to characterize the electrical properties of the gut. The addition of glucose on the mucosal side in Ussing chamber produced a significant increase (p = 0.001) in Isc in both jejunum and colon relative to the basal values in Lactobacillus probiotic group. This increase in Isc for probiotic group in jejunum is equivalent to an increase of about two times that for the basal values, while in the control group is about half fold that for the basal value. In addition, the ΔIsc after glucose addition to the large intestine was greater than the ΔIsc in the small intestine in both control and probiotic group. Moreover in both jejunum and colon, the increase in Isc for birds fed Lactobacillus was higher than their control counterparts (p ≤ 0.1). This result suggests that the addition of Lactobacillus sp. to broiler diets increased the glucose transport. Additionally, the results indicated that the conductivity of jejunal and colonic tissues remained unaffected by the dietary inclusion of Lactobacillus and support the concept that this additive enhances the maintenance and function of the epithelial barrier. In conclusion, dietary inclusion of a microbial feed additive (L. salivarius and L. reuteri) slightly increased the growth performance and improved intestinal nutrient absorption which was in association with the intestinal architecture improvement.     

益生菌取代抗生素对肉鸡生产性能的影响

当前寻找抗生素的替代品 ,以提高动物生产性能及防治感染 ,已成为业界普遍关注的问题。而益生菌以其独特的营养和免疫功能成为近年来研究热点 ,且有望作为抗生素的替代品在饲料工业中发挥重要作用。益生菌是一种有益活菌制剂 ,通过口或其他粘膜途径进入动物体内 ,然后在肠道内寄居 ,增殖有益菌 ,抑制有害菌 ,使肠道微生物和酶系统调整到平衡状态 ,以促进动物特异性或非特异性免疫机制。我国目前允许使用乳酸杆菌、芽孢杆菌、双歧杆菌、粪球菌、酵母菌等用于动物微生态制剂。本试验选取单一活菌制剂和复合活菌制剂比较其在肉鸡饲养中的使用效…     

Effect of soybean peptides on growth performance,intestinal structure and mucosal immunity of broilers

Five‐hundred 1‐day‐old broilers were randomly assigned to five groups, 100 chickens for each group. From group 1 to 3, 80, 120 and 200 mg/kg soybean peptides was added to the diets respectively; in the fourth group, 3.2 mg/kg genramycin was added; and the fifth group was the control without soybean peptides and antibiotics. At the age of 28 and 49 days, the number of goblet cells (GC), intestine intraepithelial lymphocyte, immunoglobulin A‐forming cells, the ratio of villous height and crypt depth (V/C) of broiler’s duodenum, jejunum and cecum were observed by the application of haematoxylin and eosin or histochemistry staining. The results indicated that soybean peptides added with 80–120 mg/kg could increase daily weight gain, the number of GC and V/C. Soybean peptides could modulate intestinal mucosal immunity of broilers.     

Binding of Salmonella strains to immobilized intestinal mucosal preparations from broiler chickens.

The binding kinetics of radiolabeled Salmonella california 1989/O (mannose-sensitive hemagglutinin-positive [MSHA+]) to immobilized mucus or enterocytes isolated from broiler ceca and inhibition of binding by D-mannose and sodium metaperiodate were characteristic of adherence of mannose-sensitive type 1 fimbriae of bacteria to eukaryotic mannose-containing receptors. Binding by radiolabeled strains 1989/O (in the presence of D-mannose) and S. typhimurium S 7471 N (MSHA-, non-fimbriated) indicated non-specific binding that was characterized by less binding to enterocytes and mucus and lack of inhibition by carbohydrates or prior treatment with sodium metaperiodate. Inhibition of non-specific binding to enterocytes by pretreatment with various enzymes or by the presence of tetramethylurea or p-nitrophenol (known to disrupt hydrophobic interactions) indicate involvement of multiple sites and hydrophobic bonding. Strain-specific outer-membrane preparations inhibited non-specific binding to a greater extent than did lipopolysaccharide, Escherichia coli outer-membrane preparations, or bovine serum albumin.     

低聚木糖对断奶仔猪肠道pH和肠黏膜形态结构的影响

本试验通过在日粮中添加低聚木糖探讨其对早期断奶仔猪肠道结构功能的影响。试验选用72头35日龄、体重9.81±0.41 kg杜＆#215;长＆#215;大三元杂交仔猪,随机分配成4组,每组3个重复,每个重复6头仔猪,公母各半。第1组为对照组,饲喂玉米-豆粕基础日粮;其余3组分别在各组日粮中添加0.01%、0.02%、0.04%低聚木糖作为试验组。试验预饲期2 d,正试期为28 d。于试验的最后1 d从各重复中随机选取1头仔猪屠宰,并测定胃、十二指肠、空肠、回肠、盲肠和结肠内容物的pH及十二指肠、空肠和回肠黏膜上皮的绒毛高度和隐窝深度。试验结果显示,试验组猪的胃及各肠段的pH比对照组均有所降低,尤其是0.02%低聚木糖组,差异显著（P＜0.05）;试验组各肠段的绒毛高度均高于对照组,差异显著（P＜0.05）,隐窝深度低于对照组,但差异不显著（P＞0.05）,绒毛高度与隐窝深度之比显著高于对照组（P＜0.05）。本试验结果表明,在早期断奶仔猪的日粮中添加低聚木糖,能降低胃肠道内容物的pH,改善早期断奶仔猪肠道的形态结构,以0.02%低聚木糖组效果最为明显。     

Influence of starch sources and dietary protein levels on intestinal functionality and intestinal mucosal amino acids catabolism in broiler chickens

Background: There is growing interest in carbohydrate and protein nutrition to enhance the efficiency of animal production. Reduced-crude protein diets depress environmental pollution and feeding cost, but the challenge to their adoption is maintaining digestive function and growth performance of birds. The present study was conducted to evaluate the influence of different dietary starch sources and protein levels on intestinal functionality and mucosal amino acid catabolism.Methods: Six dietary treatments, based on maize and soybean meal, were offered to 360 AA+male chicks from 6 to 35 d post-hatch as a 3 × 2 factorial array. Either waxy rice or amylose was added to a conventional maize-soy diet to provide three sources of starch with different digestion rates and relatively high and low dietary protein levels. Growth performance, parameters of intestinal functionality and concentrations of free amino acid in the portal circulation were determined.Results: In the grower phase, starch source influenced(P 0.02) weight gain as diets containing amylose supported significantly higher weight gains than waxy rice. Significant increase of ileal ATP concentrations and Na+/K+-ATPase activity were found in amylose treatment. Also, amylose decreased BrdU positive cell numbers and down-regulated m RNA expression for CASP-3. GOT activity in the ileum was higher(P 0.01) in birds offered low protein diets and there was a trend(P = 0.057) for waxy rice as a starch source to increase ileal GOT activities. There was a significant influence on the concentration of seventeen amino acids in the portal circulation with tryptophan the one exception. Waxy rice as a starch source generated 13.6% and 22.4% numerically higher concentrations of non-essential amino acids than maize and amylose, respectively.Conclusions: Amino acid catabolism in the gut mucosa is subject to nutritional regulation. Given that amino acids can be spared from catabolism in the gut mucosa by supplementation of amylose, it follows their post-enteral availability would be improved and intestinal energy would be derived more efficiently from glucose.     

酿酒酵母及EtpA酿酒酵母基因工程菌对大鼠小肠黏膜结构的影响

为了调查酿酒酵母及Etp A酿酒酵母基因工程菌对大鼠小肠黏膜生长发育状况的影响,120只健康断奶SD大鼠,随机分为空白对照组、酿酒酵母菌组、Etp A酿酒酵母基因工程菌组,分别灌胃生理盐水、酿酒酵母菌液、Etp A酿酒酵母基因工程菌液2 m L/只,持续28 d后连续3 d灌胃大肠杆菌菌液。分别取7、14、21和28 d及灌胃大肠杆菌后大鼠的十二指肠、空肠、回肠制作石蜡切片,HE染色,显微镜下观察,记录各段小肠绒毛的宽度、长度、隐窝深度及绒毛长度/隐窝深度比值(V/C)。结果显示:1)与空白对照组相比,酿酒酵母菌组及Etp A酿酒酵母基因工程菌组的十二指肠绒毛长度、V/C在第21和28天时均显著升高(P0.05);空肠绒毛长度、V/C在第28天均极显著升高(P0.01)同时隐窝深度显著下降(P0.05);回肠V/C在第28天显著升高(P0.05);各肠段绒毛宽度均无显著差异(P0.05)。2)灌胃大肠杆菌后,与Etp A酿酒酵母基因工程菌组相比,空白对照组及酿酒酵母菌组的空肠绒毛长度、V/C均极显著下降(P0.01);回肠V/C均显著下降(P0.05)。结果表明:酿酒酵母和Etp A酿酒酵母基因工程菌均可以促进肠道黏膜发育,提高消化吸收能力;Etp A酿酒酵母基因工程菌对肠道黏膜的保护作用更显著。     

乳酸杆菌对病原菌粘附肉鸡肠粘液的影响

研究嗜酸乳杆菌、禽大肠杆菌O78、大肠杆菌ATCC 25922、鸡白痢沙门氏菌和鼠伤寒沙门氏菌与肉鸡不同肠段粘液糖蛋白的粘附性能,探讨嗜酸乳杆菌对四种病原菌的粘附排斥作用.结果表明,在不同的肠道部位,嗜酸乳杆菌、鸡白痢沙门氏菌和鼠伤寒沙门氏菌与肠粘液糖蛋白的粘附能力不同,而禽大肠杆菌O78、大肠杆菌ATCC 25922在各肠段粘液上的粘附性能相近;在相同的肠道部位,所试菌与肠粘液糖蛋白的粘附能力有差异,其中嗜酸乳杆菌的粘附作用最强;嗜酸乳杆菌对所试病原菌均有不同程度的粘附排斥作用,其中对鸡白痢沙门氏菌的粘附排斥较强,而对大肠杆菌ATCC25922的则较弱.     

Effect ofBacillus amyloliquefaciens-based direct-fed microbials and antibiotic on performance,nutrient digestibility,cecal microflora,and intestinal morphology in broiler chickens

Two hundred eighty-eight 1-d-old male Arbor Acres broilers were randomly allocated to 4 treatments to examine the effect of usingBacillus amyloliquefaciens-based direct-fed microbials (DFM) to replace antibiotics in the late growth stage on performance, nutrient digestibility, cecal microflora, and intestinal morphology in broilers. The experimental diets were (1) a negative control (NC) group fed a basal diet without any antibiotics; (2) a positive control (PC) group fed the basal diet with 200 mg/kg of zinc bacitracin; (3) a test group fed the basal diet with 200 mg/kg of zinc bacitracin from d 1 to 21 and 30 mg/kg of DFM from d 22 to 42 (DFM30); and (4) a test group fed the basal diet with 200 mg/kg of zinc bacitracin from d 1 to 21 and 60 mg/kg of DFM from d 22 to 42 (DFM60). The results showed that DFM30 and DFM60 increased BW gain and improved FCR as compared with NC group (P < 0.05). Generally, the PC, DFM30, and DFM60 groups showed increased apparent total tract nutrient digestibility for DM, CP, and AME as compared with the NC group. Both the DFM30 and DFM60 groups decreased cecalEscherichia coli population as compared with the NC group, and increased the population ofLactobacillus as compared with the PC group. The PC, DFM30, and DFM60 groups increased villus height and the ratio of villus height to crypt depth compared with NC. In conclusion, dietary supplementation withB. amyloliquefaciens-based DFM during d 22 to 42 may enhance performance by increasing nutrient digestibility and improving intestinal health in birds fed diets supplemented with zinc bacitracin from d 1 to 21.     

肠道粘膜免疫研究进展

肠道粘膜不仅是机体消化、吸收营养物质的场所，而且还具有重要的免疫功能。分泌型免疫球蛋白A、上皮内淋巴细胞、微皱褶细胞和细胞因子，共同组成肠道粘膜免疫系统，以阻止食物大分子和外来微生物抗原的侵入，保护肠道的结构和正常生理功能。