养殖黑斑蛙肠道微生物结构与功能分析

利用高通量测序方法对养殖黑斑蛙(Rana nigromaculata Howell)前肠、中肠和后肠微生物结构和功能进行分析。结果表明:黑斑蛙肠道核心菌群为拟杆菌门(Bacteroidetes)、变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)。拟杆菌属(Bacteroides)、不动杆菌属(Acinetobacter)、支原菌属(Mycoplasma)和叶杆菌属(Phyllobacterium)是优势菌属。肠道中存在不动杆菌属(Acinetobacter)、气单胞菌属(Aermonas)、黄杆菌属(Flavobacterium)等潜在致病菌和芽胞杆菌(Bacillus)、乳酸杆菌(Lactobacillus)等潜在益生菌。比较发现,前肠和中肠微生物丰度和多样性均显著高于后肠,且在门和属水平菌群结构差异明显;前肠和中肠微生物功能相似,与脂代谢、氨基酸代谢、外源物质降解和代谢等代谢关联微生物丰度较高,而后肠中与碳水化合物代谢、多糖合成和代谢、辅因子和维他命代谢等关联微生物丰度较高,并且后肠中与信号转导、环境适应、免疫、膜转运、基因信息处理等关联微生物丰度高于前肠和中肠。     

应用高通量测序技术检测无特定病原体鸭粪便的微生物多样性

高通量测序技术在动物肠道微生物研究中发挥着重要作用。从3株(9个样品)无特定病原体(SPF)鸭子中收集的粪便样品放置在培养箱中培养。利用Illumina HiSeq2500平台,通过16S rRNA测序的不同区域来分析鸭肠道细菌区系。结果表明,70周龄SPF鸭的肠道微生物丰度最高的三个门是厚壁菌门、变形杆菌门和拟杆菌门,丰度最高的三个目为梭菌目、乳杆菌目和气单胞菌目,丰度最高的三个属为拟杆菌属、丛孢菌属和肠球菌属。此外,3株鸭菌株具有不同的微生物组成,但这些差异不显著。采用高通量测序方法对鸭肠道菌群进行分析,以进一步了解SPF鸭肠道菌群的分布和生物学特性,最终有利于SPF鸭的纯化。     

16S rRNA测序分析枯草芽胞杆菌喷鼻对猪鼻腔菌群影响的研究

为了探究枯草芽胞杆菌对哺乳仔猪鼻腔中微生物多样性及其功能的影响，选用1株来源于猪鼻腔的枯草芽胞杆菌NS15对哺乳期仔猪进行喷鼻试验，于喷鼻后第7天采集鼻腔拭子，随后利用16S rRNA基因高通量测序技术检测分析鼻腔拭子样本菌群结构并进行功能预测。结果显示：猪鼻腔的优势菌门为厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)。喷鼻后不影响优势菌门的组成，但是各菌门的丰度发生变化，如厚壁菌门和放线菌门的丰度增加，其中厚壁菌门中的乳杆菌属(Lactobacillus)和放线菌门中的罗氏菌属(Rothia)等有益菌属丰度增加；而变形菌门和拟杆菌门等有害菌门的丰度下降，包括变形菌门中的不动杆菌属(Acinetobacter)、嗜麦芽窄食单胞菌属(Stenotrophomonas)和鲍特菌属(Bordetella)以及拟杆菌门中的黄杆菌属(Flavobacterium)等有害菌属丰度下降。进一步Tax4Fun功能预测结果显示，喷鼻枯草芽胞杆菌NS15后，猪鼻腔中能量、氨基酸和脂类等代谢通路显著...     

工厂化和网箱养殖大黄鱼幼鱼消化道微生物群结构与功能分析

运用高通量测序方式,对两种模式养殖大黄鱼(Larimichthys crocea)幼鱼消化道菌群的结构与功能特征及其与环境菌群的相关性进行分析,结果发现:大黄鱼幼鱼消化道主要由变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes)组成。工厂化养殖大黄鱼消化道优势菌属组成比较稳定,包括乳杆菌属(Lactobacillus)、芽孢杆菌属(Bacillus)等。优势菌属中,发光杆菌属(Photobacterium)、乳杆菌属、弧菌属(Vibrio)等18个物种为两种模式养殖大黄鱼消化道的共有优势菌属;而假单胞菌属(Pseudomonas)、气单胞菌属(Aeromonas)和Escherich-ia_Shigella为主要差异菌属(P0.05)。通过相关性分析得出,饵料中菌群对消化道菌群影响较大。并且,在菌群基因参与功能方面,两种模式下幼鱼消化道菌群基因参与的主要功能相似,但工厂化养殖幼鱼消化道菌群基因参与这些功能的基因丰度高于网箱养殖的,这可能是对幼鱼的生长代谢在环境胁迫中的一种补偿作用。研究结果将为大黄鱼幼鱼消化道功能菌群的筛选与菌群调控提供理论参考。     

四川白鹅不同肠段菌群多样性比较研究

试验利用Illimina MiSeq高通量测序对70日龄四川白鹅十二指肠、空肠、回肠和盲肠内容物进行微生物多样性分析。结果显示:①4个肠段微生物群落的α多样性(菌群丰度上)存在显著差异(P0.05);②4个肠段的菌群结构在6个菌门和13个菌属的相对丰度存在显著差异(P0.05);③盲肠微生物在7个菌属(脱硫弧菌属、拟杆菌属、拟杆菌属、相炭疽杆菌属、瘤胃球菌属、韦荣球菌属和Butycricimonas菌属)的相对丰度都显著高于其他3个肠段(P0.05),但是空肠的链球菌属和回肠的SMB53菌属的相对丰度均显著高于其他3个肠段(P0.05)。结果提示:鹅不同肠段的菌群组成存在显著差异,回肠和空肠微生物都参与粗纤维的消化,盲肠消化粗纤维的能力要强于其他3个肠段。     

鸭胚胎肠道微生物定植的初步探究

肠道菌群可维持体内平衡、调节免疫系统、促进发育，在宿主生理和免疫中发挥重要作用，其与畜禽健康和生产性能密切相关。本文以鸭为模型，通过对卵黄吸收过程中不同时期的鸭胚胎整个肠道进行16s?rRNA测序，研究了卵黄吸收过程中肠道菌群的定植及其变化规律。结果表明，鸭胚肠道微生物主要由厚壁菌门、拟杆菌门、变形菌门、放线菌门组成，其中粪杆菌、拟杆菌属、肠球菌属、乳杆菌属为核心菌属，且这些肠道微生物主要参与营养物质代谢、遗传信息处理、信号传导、膜转运。说明在鸭胚不同发育阶段，肠道微生物均有定植，并随卵黄吸收和肠道发育发生变化，可为鸭肠道微生物区系的进一步研究提供参考，并为禽类胚胎的相关研究提供依据。 [关键词]肠道菌群|定植|16S?rRNA|鸭子|胚胎     

饲料中添加植物乳杆菌对细鳞鲑生长及肠道菌群多样性的影响

本试验旨在研究饲料中添加植物乳杆菌(Lactobacillus plantarum)对细鳞鲑生长及肠道菌群多样性的影响。以基础饲料为对照组,在基础饲料中添加1×106CFU/g植物乳杆菌为试验组,每组3个重复,每个重复25尾平均体重5～8 g的细鳞鲑,在室内养殖56 d后,取中后肠段内容物及其黏膜,提取微生物DNA,采用高通量测序技术检测肠道菌群多样性。结果显示:与对照组相比,饲料中添加植物乳杆菌可显著增加细鳞鲑的特定生长率(P0.05)。α多样性分析显示试验组肠道菌群多样性(Shannon指数、Simpson指数)和丰富度(Ace指数、Chao指数)均较对照组显著降低(P0.05)。β多样性分析发现试验组和对照组肠道菌群分群明显。在门水平上,试验组肠道菌群中厚壁菌门(Firmicutes)的丰度达96.03%,而对照组主要由几个丰度较大的菌门组成,分别为厚壁菌门(23. 79%)、蓝细菌门(Cyanobacteria)(23. 30%)、拟杆菌门(Bacteroidetes)(8.95%)、螺旋菌门(Spirochaetae)(6.67%)和放线菌门(Actinobacteria)(5.35%)。在属水平上,试验组肠道菌群中丰度大于1%的菌属仅有3个,为乳杆菌属(Lactobacillus)(58.94%)、微小杆菌属(Exiguobacterium)(26.00%)和肠球菌属(Enterococcus)(10.62%),总丰度达95.66%,而对照组丰度大于1%的菌属达11个,但总丰度仅为58.24%,主要有未命名_蓝细菌门(unclassified_Cyanobacteria)(23.30%)、劳尔氏菌属(Ralstonia)(11.70%)、短螺旋体属(Brevinema)(6.67%)和普氏菌属(Prevotella)(3.90%)。综上,饲料中添加植物乳杆菌能促进细鳞鲑的生长,提高其肠道中乳酸菌的比例,抑制其他菌群的生长,降低肠道菌群的多样性。     

德州驴盲肠菌群测序分析

旨在研究健康德州驴盲肠菌群分布及代谢功能。以健康德州驴盲肠内容物为检测样品,提取细菌总DNA,通过Illumina MiSeq高通量测序分析德州驴盲肠中菌群分布特点,结合PICRUSt基因预测方法分析菌群代谢功能。测序分析结果表明,在3份检测样品中共得到176 869条有效序列和39 566个OTU。Alpha多样性指数分析结果表明,3份样品的Shannon指数均大于7,样品中菌群多样性水平较高。菌群分类学组成分析结果表明,在门分类水平上相对丰度排名前10的细菌门为厚壁菌门、拟杆菌门、疣微菌门、螺旋体门、纤维杆菌门、变形菌门(Proteobacteria)、放线菌门、TM7菌门、柔膜菌门、蓝藻菌门。此外,在相对丰度排名前20的菌属中与纤维分解与代谢相关的菌属所占比例达到了35%。菌群代谢功能分析结果表明,盲肠菌群参与机体多种代谢活动,其中参与碳水化合物代谢、氨基酸代谢、能量代谢的菌群丰度相对较高。研究结果为探索德州驴肠道菌群分布与消化特点之间关系提供了理论依据。     

类志贺邻单胞菌感染对鲟鱼肠道菌群多样性的影响

采用人工肌肉注射类志贺邻单胞菌(Pseudomonas shigella)后,以针对细菌16S rRNA基因高通量测序技术进行感染鲟鱼肠道菌群组成和多样性分析,结果显示:感染组鲟鱼肠道菌群多样性指数(Chaol、ACE、observed_species、 Shannon和Simpson)均显著低于对照组(P<0.05);感染组和对照组鲟鱼肠道优势菌群均为梭杆菌门(Fusobacteria)、变形菌门(Proteobacteria)、拟杆菌门(Bacteriodia)和厚壁菌门(Firmicute),但感染组鲟鱼肠道拟杆菌门细菌丰度显著小于对照组(P<0.05),而变形菌门(特别是邻单胞菌属)细菌丰度显著大于对照组(P<0.05)。结果表明,类志贺邻单胞菌感染能导致鲟鱼肠道菌群物种多样性和丰度显著变化,为鲟鱼细菌性疾病防控提供了科学依据。     

纯种柯乐猪与巴×柯杂交猪肠道菌群结构的研究

本试验对纯种柯乐猪与巴×柯杂交猪肠道菌群结构特性及差异性进行了研究,旨在从猪肠道微生物的角度揭示纯种柯乐猪耐粗饲特性及巴×柯杂交猪对青绿饲料的适应能力,为后期微生物添加剂的设计、柯乐猪杂交利用及标准化养殖提供依据。纯种柯乐猪和巴×柯杂交猪在同等条件下养殖,达屠宰体重后(100 kg左右),随机各选3头屠宰,取十二指肠、空肠、回肠、结肠内容物,进行高通量测序和生物学信息分析。结果显示:纯种柯乐猪与巴×柯杂交猪各肠段Alpha多样性指数差异不显著(P0.05);Beta多样性分析显示,2个品种猪大部分样品交叉聚集到一起;肠道菌群结构分析显示,纯种柯乐猪和巴×柯杂交猪小肠阶段以厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)和放线菌门(Actinobacteria)为优势菌门,到了结肠阶段则是以拟杆菌门(Bacteroidetes)和厚壁菌门为优势菌门;纯种柯乐猪与巴×柯杂交猪结肠中有大量的纤维分解菌属,巴×柯杂交猪结肠中月形单胞菌属(Selenomonas)和脱硫弧菌属(Desulfovibrio)的相对丰度显著或极显著高于纯种柯乐猪(P0.05或P0.01),而消化球菌属(Peptococcus)、聚乙酸菌属(Acetitomaculum)、Leeia的相对丰度则显著低于纯种柯乐猪(P0.05);LEfSe分析后发现纯种柯乐猪结肠中富集着大量的产短链脂肪酸菌,其中纤维降解菌有聚乙酸菌属、瘤胃球菌科的不可培养瘤胃细菌4C0d_17(uncultured_rumen_bacterium_4C0d_17)、Leeia、拟杆菌纲、拟杆菌目,与纤维降解菌起协同作用的菌群有考拉杆菌属(Phascolarctobacterium)、考拉杆菌属的uncultured_Veillonellaceae_bacterium;巴×柯杂交猪结肠中富集的纤维降解菌有月形单胞菌属、柔嫩梭菌(Clostridium leptum)。上述结果表明,在整个肠道菌群结构上,纯种柯乐猪和巴×柯杂交猪的优势菌在类别上非常接近,体现了环境相同效应,纯种柯乐猪和巴×柯杂交猪的肠道菌群结构相对稳定且相似度高;在属水平上,纯种柯乐猪和巴×柯杂交猪的结肠中纤维降解菌表现出差异,纯种柯乐猪结肠内纤维降解菌的比例较高,说明引入外源血对肠道菌群结构有一定的影响,巴×柯杂交猪对粗纤维的消化能力较弱于柯乐猪。     

休眠期中华鳖消化器官中主要消化酶活性分布

为研究休眠期中华鳖中主要消化器官消化酶活性,将平均体重为672.25g的4龄鳖6只,处死后取其胃、肝、肠,采用生化方法测定其胃蛋白酶、脂肪酶和淀粉酶活性。结果表明,在中华鳖的胃、肝、前肠、中肠、后肠中均有胃蛋白酶、脂肪酶、淀粉酶。肠中蛋白酶活性由中肠、前肠、后肠递减,前肠与中肠的酶活性没有显著差异(P>0.05);肠中脂肪酶活性较胃、肝中的高;淀粉酶活性,肠中最高,胃中次之,肝脏中最低,但在肠的不同部位淀粉酶的活性没有显著差异(P>0.05)。     

Ultrastructure of the alimentary canal of the sheep scab mite, Psoroptes ovis (Acari: Psoroptidae).

The mite Psoroptes ovis causes sheep scab disease in flocks throughout much of the world. A serious impediment to the development of novel control measures for this mite is our inability to produce in vitro colonies of the mite. Here, we describe the alimentary canal of the mite with the particular aim of determining what it feeds on, as part of a longer term goal, to develop in vitro culture techniques for P. ovis. The alimentary canal of P. ovis consists of a cuticle-lined foregut and hindgut separated by a microvilli-lined midgut. The foregut is divided into a pre-oral cavity and a muscular pharynx and oesophagus. The midgut consists of three ultrastructurally discrete areas: a stomach with bi-lobed ventriculi, a colon and a post-colon. The stomach is composed of two cell types. The most common cells (Type 1) are either cuboidal or squamous depending on the degree of gut distension and possess short microvilli, a single basally located nucleus, extensive rough endoplasmic reticulum and other components suggesting active secretion. The less common cells (Type 2), possess an extensive apical network of tubules and basally food vacuoles suggesting intracellular digestion. These cells extend into the gut lumen, become free-floating and degenerate. The colon and post-colon are composed of cells similar to Type 1 stomach cells but the post-colon epithelium possesses significantly longer microvilli. Cells from these areas have not been observed to leave the surrounding epithelium and enter the gut lumen, but it is suggested that significant absorption occurs in these two areas. Faecal pellets, often containing a significant number of bacteria, leave the digestive system through the cuticle-lined anal atrium.     

Microbial diversity and structure in the gastrointestinal tracts of two stranded short-finned pilot whales (Globicephala macrorhynchus) and a pygmy sperm whale (Kogia breviceps)

Information on the gut microbiome composition of different mammals could provide novel insights into the evolution of mammals and succession of microbial communities in different hosts. However, there is limited information on the gut microbiome composition of marine mammals, especially cetaceans because of sampling constraints. In this study, we investigated the diversity and composition of microbial communities in the stomach, midgut, and hindgut of 2 stranded short-finned pilot whales (Globicephala macrorhynchus) and hindgut of a stranded pygmy sperm whale (Kogia breviceps) by using 16S rRNA gene amplicon sequencing technology. On the basis of the 50 most abundant operational taxonomic units, principal coordinate analysis, and non-metric multidimensional scaling analysis, we confirmed that the gut microbial communities of the 3 whales were different. Our results revealed that the gut microbiome of 1 stranded short-finned pilot whale GM16 was dominated by Firmicutes (mainly Clostridium) and Fusobacteria; whereas that of the other pilot whale GM19 was composed of Gammaproteobacteria and Bacteroidetes (mainly Vibrio and Bacteroides, respectively), probably caused by intestinal disease and antibiotic treatment. The gut microbiome of the pygmy sperm whale was dominated by Firmicutes and Bacteroidetes. Moreover, different gastrointestinal tract regions harbored different microbial community structures. To our knowledge, this is the first report of the gut microbiome of short-finned pilot whales, and our findings will expand our current knowledge on microbial diversity and composition in the gastrointestinal tract of cetaceans.     

Strategic Localization of Toll‐like Receptor 4 in the Digestive Tract of Blunt Snout Bream (Megalobrama amblycephala)

This study was performed to determine the localization strategies of Toll‐like Receptor 4 (TLR4) in digestive tract (oesophagus, bulbodium, foregut, midgut and hindgut) of Blunt snout bream (Megalobrama amblycephala) using immunohistochemical staining method. TLR4 positive cells were observed throughout the digestive tract. In the oesophagus, some positive reactions in lamina propria were found around small blood vessels and there were also some positive cells within the stratified squamous epithelium. Lots of positive cells were observed in the muscular layer of the oesophagus. In bulbodium, foregut and hindgut, the expression of TLR4 was mainly restricted to the apical surface of epithelial cells located at the bottom of the mucosal folds and the mesenchymal cells in lamina propria. It was very interesting that epithelial cells in the midgut, but none in other parts, had many TLR4 positive cytoplasmic granular structures which were also periodic acid Schiff positive. These findings suggested that TLR4 was expressed in a compartmentalized manner in the Blunt snout bream (M. amblycephala) digestive tract and provided novel information about the in vivo localization of pattern recognition receptors.     

Fermentation characteristics of resistant starch,arabinoxylan, and β-glucan and their effects on the gut microbial ecology of pigs: A review

Dietary fibers (DF) contain an abundant amount of energy, although the mammalian genome does not encode most of the enzymes required to degrade them. However, a mutual dependence is developed between the host and symbiotic microbes, which has the potential to extract the energy present in these DF. Dietary fibers escape digestion in the foregut and are fermented in the hindgut, producing short-chain fatty acids (SCFA) that alter the microbial ecology in the gastrointestinal tract (GIT) of pigs. Most of the carbohydrates are fermented in the proximal part, allowing protein fermentation in the distal part, resulting in colonic diseases. The structures of resistant starch (RS), arabinoxylan (AX), and β-glucan (βG) are complex; hence, makes their way into the hindgut where these are fermented and provide energy substrates for the colonic epithelial cells. Different microbes have different preferences of binding to different substrates. The RS, AX and βG act as a unique substrate for the microbes and modify the relative composition of the gut microbial community. The granule dimension and surface area of each substrate are different, which influences the penetration capacity of microbes. Arabinose and xylan are 2 different hemicelluloses, but arabinose is substituted on the xylan backbone and occurs in the form of AX. Fermentation of xylan produces butyrate primarily in the small intestine, whereas arabinose produces butyrate in the large intestine. Types of RS and forms of βG also exert beneficial effects by producing different metabolites and modulating the intestinal microbiota. Therefore, it is important to have information of different types of RS, AX and βG and their roles in microbial modulation to get the optimum benefits of fiber fermentation in the gut. This review provides relevant information on the similarities and differences that exist in the way RS, AX, and βG are fermented, and their positive and negative effects on SCFA production and gut microbial ecology of pigs. These insights will help nutritionists to develop dietary strategies that can modulate specific SCFA production and promote beneficial microbiota in the GIT of swine.     

苜蓿草粉对禾花鲤蛋白酶和淀粉酶活性影响的研究

选取来源一致、规格整齐的2龄禾花鲤1 200尾,采用单因子完全随机设计,分为5个处理,每处理3个重复,每重复80尾鱼,分置于15个试验池中。各处理苜蓿Medicago sativa草粉的添加量分别为0（对照组）、40（试验Ⅰ组）、80（试验Ⅱ组）、120（试验Ⅲ组）和160 g/kg（试验Ⅳ组）,正试期50 d,观测苜蓿草粉对禾花鲤前、中、后肠及肝胰脏蛋白酶和淀粉酶活性的影响。结果表明：1）添加苜蓿草粉对前肠蛋白酶活性有显著影响 (P<0.05),其中试验II组显著高于对照组和试验Ⅳ组,但和试验Ⅰ、Ⅲ组差异不显著 (P>0.05)。添加苜蓿草粉对中、后肠及肝胰脏蛋白酶活性均无显著影响 (P>0.05),但它们有相同的变化趋势,即试验Ⅰ、Ⅱ、Ⅲ组鱼的蛋白酶活性均高于对照组。2）鲤鱼的前肠、中肠、后肠蛋白酶活性依次减弱,而肝胰脏的蛋白酶活性远低于肠道。3）添加苜蓿草粉后前肠及中肠淀粉酶活性比较,试验II组显著高于对照组 (P<0.05),其余各组与对照组差异不显著 (P>0.05),后肠淀粉酶活性与对照组无显著差异 (P>0.05)。添加苜蓿草粉能提高鲤鱼肝胰脏淀粉酶活性,其中试验Ⅱ组显著高于对照组 (P<0.05),其余试验组与对照组无显著差异 (P>0.05)。4）禾花鲤前、中、后肠及肝胰脏4部分淀粉酶的活性有较大的不同,肝胰脏>后肠>中肠>前肠。     

Characteristics of mature oocytes from four species of marine teleosts

The morphology and histology of the digestive tract of the branchiuran crustacean, Chonopeltis australis Box shall, 1976 are described from serial sections. The foregut is differentiated into a preoral cavity, containing the mandibles and tongue, an ascending oesophagus, with an H-shaped lumen invested with longitudinal, circular and dilator muscles, a horizontal oesophagus with a star-shaped lumen and lacking longitudinal and dilator muscles, and an oesophageal funnel consisting of inner and recurrent walls. The midgut is differentiated into anterior and posterior chambers, separated by an S-shaped muscular tube. The arborescent midgut glands open laterally into the anterior part of the anterior midgut. Columnar epithelial cells line the anterior midgut whereas tall, papilliform cells are present in the epithelium of the posterior midgut. The transition from posterior midgut to hindgut is marked by the presence of very tall epithelial cells. The terminology describing the various parts of the digestive tract of branchiurans is discussed.     

猪肠道微生物组成、影响因素及其对重要经济性状的影响研究进展

肠道微生物在调节宿主生理机能、代谢和免疫功能等方面发挥着非常重要的作用,是影响猪健康和重要经济性状表型的重要因素之一。近年来,人们对猪肠道微生物的研究和了解越来越深入,了解猪肠道微生物组成将有助于为从肠道菌群方向入手改善猪群健康和提高生产性能提供参考。作者首先综述了不同发育阶段、不同肠道部位以及主要商品猪和中国地方猪肠道核心菌群组成;其次系统总结了宿主遗传背景、饲粮种类、性别、环境以及抗生素、益生菌和饲料添加剂使用等因素对猪肠道微生物组成的影响;最后概述了猪肠道微生物主要功能及其对饲料利用率、脂肪沉积、宿主行为和免疫炎症等方面的影响。     

Impaired immune responses in broiler hatchling hindgut following delayed access to feed

One of the key stimulators of intestinal development in the chick is physical exposure to feed, while feed withholding delays the onset of gut development. A delay of 24-72 h in onset of feeding is quite common in the poultry industry due to variation in hatching time and hatchery treatments. As intestinal development occurs in concert with the development of the gut associated lymphoid tissue (GALT), we investigated the effects of short term feed withholding on development of GALT in broiler hatchlings. GALT activity was determined by antibody production (systemic and locally in the gut), distribution of B and T lymphocytes in the gut, expression of lymphocyte specific genes, and distribution of B and T lymphocytes in the cloacal bursa. Our findings show that while development of GALT in the foregut (duodenum, jejunum, ileum) was only slightly and temporarily impeded by feed withholding, GALT activity in the hindgut and the gut-related cloacal bursa was significantly delayed during the first 2 weeks of life: Systemic and intestinal antibody responses following rectal immunization to antigen were lower, colonization of the hindgut (cecum and colon) by T and B lymphocytes was delayed, as well as the expression of chIL-2 mRNA in hindgut T lymphocytes. We also found that the increase of B and T population size in the cloacal bursa was delayed with time. Full recovery occurred from 2 weeks of age. The 2-week vulnerable period should be seriously considered in circumstances where hatchlings are in transit for extended periods from hatcheries to farms.     

The combined use of whole Cuphea seeds containing medium chain fatty acids and an exogenous lipase in piglet nutrition.

In search for an alternative for nutritional antimicrobials in piglet feeding, the effects of adding whole Cuphea seeds, as a natural source of medium chain fatty acids (MCFA), with known antimicrobial effects, and an exogenous lipase to a weaner diet were studied. The foregut flora, the gut morphology, some digestive parameters and the zootechnical performance of weaned piglets were investigated. Thirty newly weaned piglets, initial weight 7.0 +/- 0.4 kg, were divided according to litter, sex and weight in two groups (control diet; Cuphea + lipase diet). The Cuphea seeds (lanceolata and ignea) (50 g kg(-1)) were substituted for soybean oil (15 g kg(-1)), Alphacell (25 g kg(-1)) and soy protein isolate (10 g kg(-1)) in the control diet. Also 500 mg kg(-1) microbial lipase was added to the Cuphea diet. The piglets were weighted individually on days 0, 3. 7, 14 and 16. Feed intake was recorded per pen during days 0 to 3, 3 to 7, 7 to 14 and 14 to 16. On day 7 five piglets of each experimental group were euthanized for counting the gastric and small intestinal gut flora and for gut morphology at two sites of the small intestine (proximal, distal). The results indicate a trend towards improved performances parameters by feeding Cuphea + lipase. The enzymic released MCFA (1.7 g kg(-1) fresh gastric contents) tended to decrease the number of Coliforms in the proximal small intestine, but increased the number in the stomach and distal small intestine. With Culphea, the number of Streptococci was significantly lower in small intestine, but not in the stomach, while the number of Lactobacilli was significantly lower in the distal small intestine and tended to be lower in the stomach and proximal small intestine. No differences between the diets were noted for the total anaerobic microbial load in the stomach or in the gut. Feeding Cuphea + lipase resulted in a significantly greater villus height (distal small intestine) and a lesser crypt depth (proximal and distal small intestine) and greater villus/crypt ratio depth (proximal and distal small intestine). The intra-epithelial lymphocyte (IEL) counts per 100 enterocytes were significantly decreased in the proximal small intestine and tended to decrease in the distal small intestine by feeding the Cuphea + lipase diet. Both phenomena are indicative for a more healthy and better functional state of the mucosa. Present results are in line with foregoing research, showing that manipulation of the gut ecosystem by the enzymic in situ released MCFA in the stomach and foregut can result in improved performances of the piglets, which makes the concept a potential alternative for in-feed nutritional antibiotics.