产肠毒素大肠杆菌对仔猪肠道黏膜屏障功能的影响及其损伤修复研究进展

完整的肠道黏膜结构是其功能实现的基础,也是畜禽健康生长的重要保障。产肠毒素大肠杆菌(ETEC)是引起仔猪腹泻的主要病原体之一。ETEC及其代谢产物可引起肠道上皮细胞代谢紊乱,破坏黏膜结构,导致功能失调,进而损害畜禽肠道健康。本文就ETEC对仔猪肠道黏膜屏障功能的影响及其损伤修复研究进展作一综述,旨在为养猪生产中预防和治疗仔猪细菌性腹泻提供参考。     

家禽热应激肠道黏膜屏障损伤及营养性修复研究进展

家禽肠道既是消化和吸收营养物质的重要器官,又是保持机体内环境稳定的先天性屏障,正常肠道内的黏膜屏障对于维持家禽的健康至关重要。在热应激过程中,家禽的肠黏膜是热应激机体损伤的敏感部位,容易造成肠黏膜损伤,破坏其屏障功能,阻碍肠道正常代谢功能,降低家禽的生产性能。文章主要就热应激对肠道黏膜屏障的损伤及营养性修复作用进行综述,旨在为缓解家禽肠道黏膜损伤的营养性物质的开发与应用提供参考依据。     

胃肠黏膜屏障及应激对其的影响和干预措施

应激可破坏胃肠道上皮细胞间紧密连接完整性,损伤胃肠黏膜屏障,并引发胃肠黏膜屏障障碍,增加其通透性,最终导致机体产生炎症反应,对其进行干预则可降低应激对胃肠通透性的影响。本文主要对胃肠黏膜屏障构成及其功能、胃肠黏膜屏障功能的评价和胃肠通透性的测定、应激对胃肠黏膜屏障的影响及干预措施进行了综述,以期为缓解应激对胃肠黏膜屏障功能的影响提供参考。     

热应激条件下色氨酸调控畜禽肠道免疫功能的研究进展

随着全球气候变暖，夏季高温环境下热应激严重影响畜禽健康，降低畜禽生产效率和产品品质，给养殖业造成了极大的经济损失。色氨酸属于芳香族氨基酸，是畜禽的必需氨基酸，同时也是多种生物活性分子的前体物质，可以调节机体肠道屏障和免疫功能，降低动物的应激反应。本文就热应激对畜禽肠道屏障及免疫功能的影响和色氨酸代谢对肠道屏障及免疫功能的调控作用进行综述，并探讨了色氨酸及其代谢产物调控热应激条件下畜禽肠道屏障及免疫功能的作用机制，以期为生产中应用色氨酸缓解畜禽热应激提供参考。     

微生态制剂作用机制及对畜禽免疫功能的影响

微生态制剂在促进畜禽肠道功能及肠腔微生物区系稳态方面效果显著。肠道上皮及黏膜是机体有效防止外源性病原体侵入的第一道屏障,对于维护机体健康发挥重要作用。微生态制剂可以增强肠上皮细胞紧密连接及免疫物质的分泌,改善肠道黏膜屏障,维护机体健康。文章综述了微生态制剂对畜禽肠道的作用机制及其对畜禽免疫器官、免疫细胞及因子、肠道黏膜免疫功能的影响,以期为微生态制剂的研发及其在畜禽生产中的应用提供新思路。     

霉菌毒素对肠道黏膜屏障功能影响的研究进展

肠道作为抵抗外部污染物的第一道屏障，其黏膜屏障功能对维持畜禽健康至关重要。霉菌毒素作为广泛存在于饲料原料中的真菌有毒次生代谢产物，可通过破坏肠上皮的形态、组织完整性和肠道菌群平衡，以及改变黏蛋白单糖组成、肠黏蛋白和细胞因子的表达来破坏肠黏膜的屏障功能，从而造成肠黏膜损伤，降低畜禽的生产性能。本文主要对霉菌毒素对肠黏膜屏障的作用及机制进行了概述，旨在为养殖业饲料霉菌毒素的预防提供理论参考。 [关键词] 霉菌毒素|肠黏膜屏障|饲料     

肠道黏膜屏障机能及其调控研究进展

肠道不仅仅是机体消化、吸收营养物质的主要场所,也是机体的一道防御屏障。肠道黏膜屏障包括黏膜生物屏障、机械屏障、化学屏障和免疫屏障,不论是哪一种肠道黏膜屏障受到损伤,都会导致机体不同程度的伤害,与一些疾病的发生密切相关。本文就肠道黏膜屏障机能及其调控研究进展进行综述,为进一步认识肠道黏膜屏障及治疗由其损伤引起的疾病提供参考和帮助。     

畜禽呼吸道黏膜屏障的结构和功能及其改善措施

呼吸道黏膜屏障是机体防御的重要屏障,主要包括机械屏障、化学屏障、微生物屏障和免疫屏障,各屏障有机地结合在一起,共同阻止有害物质的侵袭,保护呼吸道健康。畜禽舍内粉尘、有害气体及温度、湿度等因子容易引起呼吸道疾病,导致呼吸道黏膜损伤,加重畜禽病情,甚至诱发脏器病理损伤。本文主要通过总结呼吸道黏膜屏障的结构和功能以及改善畜禽呼吸道黏膜屏障的措施,为深入研究呼吸道黏膜屏障进而防治畜禽呼吸道疾病提供理论依据。     

热应激对家禽肠道健康的影响

热应激是影响家禽生产潜力的主要环境问题之一,对家禽的生理、免疫和肠道功能等产生不良影响,最终影响家禽的生产性能.肠道是家禽消化和吸收营养物质的重要器官,也是机体易受热应激损伤的主要部位,热应激下肠道黏膜屏障完整性和功能受损,影响家禽营养物质吸收和生长发育.该文从热应激对家禽肠道完整性、肠道菌群、肠道黏膜的氧化状态和肠道...     

断奶仔猪肠道屏障功能的研究进展

仔猪的断奶过程伴随着心理、环境、营养三大应激,小肠的屏障功能极易受到应激影响而遭受损伤,使得小肠黏膜通透性增加,有害物质进入机体,引发各种疾病,给养猪业带来极大的危害。文章介绍了评估肠道屏障功能的主要方法,综述了断奶日龄、断奶应激、采食量和日粮组成等对仔猪旁细胞屏障及跨细胞屏障的影响,以及缓解小肠屏障功能损伤的方法。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.