胃肠道黏膜免疫与动物营养调控

黏膜免疫系统(mucosal immune system,MIS)主要指呼吸道、肠道及泌尿生殖道黏膜固有层和上皮细胞下散在的无被膜淋巴组织,以及某些带有生发中心的器官化淋巴组织,如扁桃体、小肠派氏集合淋巴结(Peyer's patches,PP)及阑尾等[1],由黏膜结合淋巴组织、致敏淋巴细胞散布途径和黏膜     

胃肠道菌群与黏膜免疫在围产期奶牛健康中的作用

胃肠道菌群的变化在动物健康和疾病中扮演重要角色,越来越多的研究证据将机体的免疫系统与胃肠道菌群联系了起来。其主要机制可能是菌群紊乱导致菌群-免疫互作失调,营养代谢与能量调控失衡,免疫系统受损,最后诱发疾病。围产期奶牛面临维持机体正常生理代谢的严峻挑战,奶牛在围产期容易感染多种疾病,给牧场带来了严重的经济损失。最近的研究表明,围产期奶牛瘤胃菌群紊乱是导致生产性疾病发生的重要诱因,胃肠道菌群与宿主黏膜免疫系统之间的互作在维持胃肠道动态平衡和抑制炎症中起着关键作用。本文综述了围产期奶牛胃肠道菌群变化特征及胃肠道黏膜免疫系统组成,并讨论了菌群与黏膜免疫互作机制在维持奶牛健康中发挥的重要作用,最后介绍了菌群紊乱与免疫失衡介导的奶牛生产性疾病,旨在为探索围产期奶牛饲养管理及疾病防控提供新思路。     

植物单宁防治反刍动物胃肠道线虫感染的研究进展

胃肠道线虫感染对反刍动物生产造成了巨大的经济损失。采用驱虫药进行胃肠道线虫防治工作时药物残留等问题严重,而饲喂具有抗虫作用的植物及其提取物则因其天然、高效的特点可以研究作为替代驱虫药的新型驱虫措施。本文主要对植物单宁的抗虫作用机理、常见的富含单宁植物的抗虫作用研究成果进行了综述。     

动物胃肠道黏膜免疫简述

胃肠道作为机体营养物质的消化吸收场所,也是动物机体对肠道有害物质免疫防护的重要部位.胃肠道黏膜免疫是机体免疫系统的一个重要组成部分,是动物胃肠道免疫防护的第一道屏障,受到复杂且特殊抗原的影响,通过营养调控措施增强机体黏膜免疫的功能,对动物机体作用重大.     

嗜线虫真菌Duddingtonia flagrans防制绵羊胃肠道线虫病

将 30只 4～ 6月龄羊分为 2组 ,分别在各自的围栏草场中放牧。用毛圆线虫和血矛线虫为主的第 3期幼虫对所有羊只人工感染 2次后 ,一组羊按每千克体重 1× 10 6 个的剂量每天饲喂嗜线虫真菌的厚垣孢子制剂 ;另一组羊作对照 ,仅饲喂等量的上述制剂基质——小麦。第 2次人工感染后 8周 ,2组羊粪便 EPG基本相近 ,但与对照组相比较 ,真菌组粪便培养物中感染性幼虫减少了 6 9.7% ;草场草样中感染性幼虫数也较对照组减少 6 7.8%。再把以上 2组羊驱虫后分别放养于上述围栏草场 ,8周后真菌组羊粪便 EPG较对照组减少 87.3% ;草场感染性幼虫也较对照组减少82 .6 %。上述结果显示 ,嗜线虫真菌 Duddingtonia flagrans在绵羊胃肠道寄生性线虫病生物防制中具有良好的应用前景     

山羊胃肠道线虫调查及防治效果观察

为了摸清山羊胃肠道线虫的感染种类、感染强度及感染率进行了本次调查,结果发现感染率高达１００％,感染强度大,ＥＰＧ达３４１６,最多可达６９００,且混合感染严重,最多达７种,最少也有４种,选用阿福丁、左旋咪唑及丙硫苯咪唑进行驱虫,并观察了增重效果。结果,三种药物对山羊胃肠道线虫成虫均有好的驱杀作用,投药第７天时平均虫卵减少率分别为１００％、９０．６３％及１００％,对幼虫的作用以阿福丁为优;羊驱虫与否的     

断奶仔猪胃肠道免疫及营养研究

胃肠道不仅是营养物质消化吸收的重要场所,也是仔猪免疫系统的重要组成部分。早期断奶仔猪免疫系统发育不完善,由于断绝了母乳供给的免疫因子和消化道发育的营养活性物质,胃肠道功能紊乱,易形成断奶综合征,从而降低断奶仔猪成活率和生长发育性能,现对国内外断奶仔猪胃肠道免疫方面的最新研究进展进行综述。     

黏膜免疫系统及黏膜免疫研究进展

黏膜免疫系统是由呼吸道、胃肠道和泌尿生殖道黏膜相关的淋巴组织以及一些外分泌腺体(唾液腺、泪腺、乳腺)处的淋巴组织所组成的免疫系统,受黏膜表面抗原刺激而产生局部特异性免疫应答。黏膜免疫是机体免疫重要的组成部分,是机体抵抗感染的第一道屏障。     

21世纪澳大利亚家畜胃肠道寄生线虫防治策略

澳大利亚家畜业的经营方法，基本都是全年实施放牧，因而寄生线虫是一个重大问题。对于绵羊，线虫寄生早巳是经济上最重要的发病原因，对于牛群，随着病毒性疾病及布鲁氏菌病和结核的灭绝，线虫寄生的相对重要性也在急骤增长。在线虫寄生的绵羊群中普遍出现的对苯并咪唑类(benzimidazoles)、左咪唑(levamizole)和甲噻嘧啶(morantel)产生的高度耐药性，促使牧主转而实施新的防治策略。     

胃肠道营养对动物机体免疫的影响

本文综述了胃肠道的营养途径和几种营养素对胃肠道局部及机体全身免疫系统的影响及存在的问题。     

Vaccination against gastrointestinal nematode parasites of ruminants using gut-expressed antigens

To date, proteins isolated from the surface of the gut of gastrointestinal nematodes, particularly Haemonchus contortus, have generally proved to be useful protective antigens and several are being progressed towards recombinant protein-based vaccines. This paper describes the properties of some of the most promising antigens and summarises their performance in laboratory and field based trials. The antigens described include contortin, H11, H-gal-GP, GPI and cysteine proteinases. In addition, the discussion addresses the utility of selected antigens to protect against co-infecting nematode species such as Teladorsagia circumcincta and against related nematode infections such as Ostertagia ostertagi in cattle.     

国产表阿佛菌素驱除山羊胃肠道线虫的临床试验

对145只自然感染胃肠线虫的山羊进行了国产表阿佛菌素驱除胃肠线虫的临床疗效试验.单次给药治疗21 d后,其0.1、0.2、0.4 mg/kg组的精计驱虫率均为100%,驱净率分别为100%、100%和90%～100%,粗计驱虫率分别为100%、100%和99.4%～100%,均显著优于阳性对照组(0.15%、0和0)和对照药物盐酸左旋咪唑组(38.4%、35%～85%和66.5%～85.9%)(P＜0.05或P＜0.01),表明表阿佛菌素具有明显的驱除胃肠线虫作用,其临床推荐剂量为0.2 mg/kg.     

饲用益生菌对动物肠道免疫调节的作用机理

益生菌即一类以活菌为主的新型饲料添加剂,其活菌能在动物肠道内定植,维护肠道菌群平衡,并刺激肠黏膜免疫系统,引起体液免疫和细胞免疫应答,从而增强机体抗病力.本文对益生菌的免疫刺激及其作用机理进行综述.     

Responses in milk production to the control of gastrointestinal nematode and paramphistome parasites in dairy cattle

Objective To determine the effect of treating naturally acquired gastrointestinal nematode and paramphistome infections on milk production in dairy cattle.
Design A field trial.
Animals One thousand two hundred and thirty nine dairy cows.
Procedure Cows were either not treated or treated with 4.5 mg/kg oxfendazole, 16.6 mg/kg oxyclozanide or 4.5 mg/kg oxfendazole and 16.6 mg/kg oxyclozanide in March, May and August.
Results A significant increase in milk production, averaging 0.4 L (SE 0.2) per day, was seen when dairy cows infected with gastrointestinal nematodes and paramphistomes were treated with oxfendazole or oxfendazole and oxyclozanide in March, May and August. Cows treated with oxyclozanide alone at these times produced no more milk than untreated cows.
Faecal egg counts confirmed that oxyclozanide treatment reduced paramphistome populations and oxfendazole treatment reduced nematode populations in cows over the 7-month monitoring period.
Conclusion When dairy cows infested with gastrointestinal nematodes and paramphistomes were treated with oxfendazole alone or oxfendazole and oxyclozanide in March, May and August milk production increased.     

Survey of gastrointestinal nematode parasites in Saskatchewan beef herds

A survey of gastrointestinal parasites in Saskatchewan beef herds was conducted over the summer of 2014. Fecal samples were collected on 3 occasions during the summer grazing season from beef cows and calves from 14 herds. The mean number of strongylid eggs per gram of feces recovered from calves increased 9-fold (95% CI: 4.5 to 18) over the summer period, while egg counts in the cows remained constant over the same period. The prevalence and infection intensities of gastrointestinal nematode parasites in cow-calf herds in Saskatchewan were comparable to what is seen in cattle grazing in the northern regions of the United States and for which anthelmintic treatments have resulted in positive production benefits.     

Management of gastrointestinal nematode parasites on sheep farms in New Zealand

AIM: To report current farmer opinions and farming practices relating to control of gastrointestinal nematodes and anthelmintic resistance on sheep farms in New Zealand.

METHODS: An interview-based cross-sectional study of grazing management and anthelmintic useage was conducted by veterinarians on 80 randomly selected sheep farms in New Zealand.

RESULTS: Useable data were returned by 74/80 (92%) farmers who participated in the study. However, despite contacting 400 farmers the target sample size of 100 farms was not reached. The results indicated that only 31% of farms had previously tested for drench resistance, that effective quarantine-drenching of imported stock was not always carried out, and that farmers were more likely to integrate cattle than ewes into their grazing management of lambs. Furthermore, the number of drenches given to lambs had changed little in 25 years. The use of faecal egg counting by farmers has increased.

CONCLUSIONS: Dependence on anthelmintics continues to be high on sheep farms in New Zealand. Whilst the number of drench treatments has changed little, there is more widespread use of persistent or long-acting treatments. Farmers need to be encouraged to monitor the resistance status of nematode populations on their farms and use this information to develop strategies aimed at maintaining susceptible alleles within the parasite populations and conserving the efficacy of existing drug families.     

地塞米松对仔猪十二指肠黏膜免疫的影响

为了探讨地塞米松对仔猪肠道黏膜的影响,选用福州周边某猪场30日龄仔猪30头,随机分为6组,3组为试验组,3组为对照组,试验Ⅰ、Ⅱ、Ⅲ组分别肌肉注射1 mL、2 mL、3 m L地塞米松,对照组Ⅰ、Ⅱ、Ⅲ组分别肌肉注射1 mL、2 m L、3 mL生理盐水;药物试验7 d后,取十二指肠固定、脱水、包埋、切片,经HE染色、阿利新蓝-过碘雪夫(AB-PAS)染色,检测地塞米松对肠道绒毛高度、隐窝深度、绒毛高度和隐窝深度比值、黏液细胞、上皮内淋巴细胞数量的影响。结果表明:长时间过量注射地塞米松抑制肠绒毛生长,显著降低肠绒毛长度和隐窝深度比值,显著性降低仔猪十二指肠上皮酸性黏多糖阳性细胞和上皮内淋巴细胞数量。可见,持续过量注射地塞米松将影响十二指肠黏膜免疫功能。     

Management of gastrointestinal nematode parasites on sheep farms in New Zealand

AIM: To report current farmer opinions and farming practices relating to control of gastrointestinal nematodes and anthelmintic resistance on sheep farms in New Zealand. METHODS: An interview-based cross-sectional study of grazing management and anthelmintic usage was conducted by veterinarians on 80 randomly selected sheep farms in New Zealand. RESULTS: Useable data were returned by 74/80 (92%) farmers who participated in the study. However, despite contacting 400 farmers the target sample size of 100 farms was not reached. The results indicated that only 31% of farms had previously tested for drench resistance, that effective quarantine-drenching of imported stock was not always carried out, and that farmers were more likely to integrate cattle than ewes into their grazing management of lambs. Furthermore, the number of drenches given to lambs had changed little in 25 years. The use of faecal egg counting by farmers has increased. CONCLUSIONS: Dependence on anthelmintics continues to be high on sheep farms in New Zealand. Whilst the number of drench treatments has changed little, there is more widespread use of persistent or long-acting treatments. Farmers need to be encouraged to monitor the resistance status of nematode populations on their farms and use this information to develop strategies aimed at maintaining susceptible alleles within the parasite populations and conserving the efficacy of existing drug families.