经密码子优化的小反刍兽疫病毒H蛋白在昆虫细胞中的表达

小反刍兽疫病毒（peste des petits ruminants virus,PPRV）属于副黏病毒科、麻疹病毒属成员。本实验室已经证明,该病毒的囊膜糖蛋白H蛋白在未经密码子优化条件下难以在昆虫细胞中表达。本研究首先对其密码子进行优化,然后构建了在昆虫细胞中表达该蛋白的重组杆状病毒。经Western-blot和间接免疫荧光试验表明,该重组杆状病毒在昆虫细胞中能够表达H蛋白,但表达量相对较低。     

World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for evaluating the efficacy of ectoparasiticides against myiasis causing parasites on ruminants

These guidelines have been prepared to assist in the planning, conduct and interpretation of studies for the assessment of efficacy of ectoparasiticides against the myiasis causing parasites of ruminants. These guidelines specifically focus on larvicidal efficacy against myiasis causing flies. Information is provided on the selection of animals, dose determination and dose confirmation studies, field studies, record keeping and result interpretation. These guidelines advocate the use of pen facilities for dose determination and dose confirmation studies for defining therapeutic and persistent efficacy. These guidelines are also intended to assist investigators on how to conduct specific experiments, to provide specific information for registration authorities involved in the decision-making process, to assist in the approval and registration of new ectoparasiticides, and to facilitate the world-wide adoption of standard procedures.     

World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for evaluating the efficacy of ectoparasiticides against biting lice, sucking lice and sheep keds on ruminants

These guidelines have been prepared to assist in the design, implementation and interpretation of studies for the assessment of the efficacy of ectoparasiticides against biting and sucking lice and sheep keds on ruminants. Information is provided on the selection of animals, dose determination, dose confirmation and field studies, record keeping and result interpretation. These guidelines advocate the use of pen facilities for dose determination and dose confirmation studies for defining therapeutic and persistent efficacy. These guidelines are also intended to assist investigators on how to conduct specific experiments, to provide specific information for registration authorities involved in the decision making process, to assist in the approval and registration of new ectoparasiticides, and to facilitate the world-wide adoption of standard procedures.     

Identification of Pasteurella multocida isolates of ruminant origin using polymerase chain reaction and their antibiogram study

A total of 100 isolates of Pasteurella multocida from various ruminant species (cattle, buffalo and sheep) belonging to different parts of country were identified using Pasteurella multocida-PCR (PM-PCR) and capsular PCR assays. PM-PCR revealed an amplicon of approximately 460 bp in all the isolates tested. As regards capsular PCR, 36 of 38 cattle isolates and 30 of 34 buffalo isolates were found to belong to capsular serogroup B whereas rest of the cattle and buffalo isolates belonged to serogroup A of P. multocida. In case of sheep, a total of 26 out of 28 isolates were positive for serogroup A specific PCR while remaining 2 amplified a PCR product specific for serogroup F of P. multocida. All the isolates were subjected to antibiotic sensitivity testing using 17 different antibiotics. Enrofloxacin was found to be most potent antibiotic as it was effective against 94% of the isolates followed by ofloxacin (93%), chloramphenicol (93%), doxycycline (89%), tetracycline (86%) and ciprofloxacin (84%). Vancomycin, bacitracin and sulfadiazine were ineffective against P. multocida isolates showing 84%, 75% and 82% resistance, respectively. Further, the antibiogram also revealed the development of resistance against multiple drugs among various isolates of the organism.     

小反刍兽疫H蛋白主要抗原表位的原核表达

目的表达小反刍兽疫病毒H蛋白的主要抗原位点用于检测与预防。方法用DNAStar分析小反刍兽疫病毒H基因的主要抗原位点,采用逆转录聚合酶链式反应(RT-PCR)技术,从病羊组织中扩增PPRV的H基因的主要抗原位点并克隆到原核表达载体PET-28b中,最后用PCR、酶切和测序分析对重组质粒进行鉴定;将重组质粒转化到大肠杆菌Rosetta中,经不同浓度的IPTG诱导表达PPRVH基因的主要抗原位点;用SDS-PAGE和Western-blotting分析所有蛋白的表达。结果将RT-PCR产物电泳,得到与预期大小相符的特异性片段;对重组质粒PET-28b-H66-249和PET-28b-H281-550酶切后,均出现预期相符的片段;DNA测序表明插入片段的序列与小反刍兽疫H蛋白基因完全一致,其大小分别为569bp和831bp;将重组表达的蛋白经SDS-PAGE和Western-blotting检测,证明所有的蛋白均得到表达。结论成功表达了PPRVH基因的主要抗原蛋白,为日后的检测与预防工作奠定了基础。     

不同氮源对反刍动物饲料可利用粗蛋白的影响

本试验应用体外培养技术研究了不同氮源对反刍动物饲料可利用粗蛋白(utilizable crude protein,uCP)的影响,以及不同氮源在培养发酵过程中降解损失的情况。将4种氮源,即尿素、赖氨酸、蛋氨酸和酪蛋白水解物,分别添加到肉牛的典型基础日粮中(粗蛋白,CP14.1%),配制成4种日粮,并使各日粮的粗蛋白水平相近(约20%),作为试验日粮。以未添加氮源的基础日粮作为对照日粮。应用Zhao和Lebzien(2002)的体外培养法测定了4种试验日粮和对照日粮的uCP。结果表明,添加尿素、赖氨酸、蛋氨酸和酪蛋白水解物,均能够有效地提高基础日粮的uCP(P<0.05)。在这4种氮源中,赖氨酸提高uCP的效果最好。在培养发酵过程中,尿素、赖氨酸、蛋氨酸和酪蛋白水解物的氨态氮损失分别占粗蛋白质的72.9%、22.8%、55.2%和70.3%。     

关于建设陕西草食畜牧业科技创新体系的构想

在总结陕西草食畜牧业生产现状及面临的挑战的基础上，通过对国内外草食畜牧业科技发展水平以及优势的分析，针对性地指出了该构想的基本思路、发展目标、重点方向和领域，进而就怎样实施陕西草食畜牧业科技创新工程提出了一系列对策措施。     

基于H蛋白表位合成肽的小反刍兽疫病毒抗体间接ELISA检测方法的建立

本研究旨在建立针对小反刍兽疫病毒（peste des petits ruminants virus,PPRV）H蛋白抗体的iELISA检测方法。以筛选的H蛋白B细胞表位为基础,选择反应原性较好的4个抗原表位肽串联后合成作为包被抗原,优化各步反应条件及筛选各种缓冲液,并确定检测临界值。经优化后,多表位抗原肽的最佳包被量为1.5×10^-6 μg·孔^-1,血清临界稀释度为1：100,酶标二抗最佳稀释度为1：80 000;包被液为碳酸氢盐缓冲液,血清和二抗稀释液均为PBST溶液,封闭液为2% BSA溶液;阴、阳性临界值为0.25。不同血清的检测结果表明,批内及批间检测结果变异系数均小于10%,证明该方法具有良好的稳定性;对羊痘、口蹄疫、蓝舌病阳性血清的检测均为阴性,说明该方法具有良好的特异性;与ID-Vet公司的cELISA试剂盒对306份临床血清平行检测,两者相对符合率为92.81%。该研究所建立的PPRV H蛋白抗体iELISA检测方法特异、稳定、敏感,操作比cELISA简便快捷,省时省力,可用于临床小反刍兽疫抗体检测。     

反刍动物灌注营养技术原理与应用

本文综述了反刍动物灌注营养技术的发展过程、操作方法、操作技巧及该技术在反刍动物营养研究中应用的可能性。     

小反刍兽疫的诊断与综合防控措施

小反刍兽疫是由小反刍兽疫病毒引起的一种急性、亚急性传染性疾病,主要感染绵羊、山羊及一些野生小反刍动物,发病率和死亡率均较高,给广大农牧民和养殖场造成巨大的经济损失。因此,对该病的诊断及综合防控措施进行概述,以期为该病的防控提供参考。