谷氨酰胺对肉鸡屠宰性能及部分免疫指标的影响

本试验选用270只1日龄AA肉鸡随机分成3组,分别在基础日粮中添加0%,0.2%,0.4%的谷氨酰胺(Gln),于21、42日龄时测定各组屠宰性能及部分免疫指标的影响.结果表明日粮中添加0.2%,0.4%的Gln对肉仔鸡生长、屠宰性能有较好的促进作用,能够加快胸腺和脾脏发育,在延缓法氏囊退化方面有积极的作用效果.日粮中添加0.2%,0.4% Gln能够提高肉鸡屠宰性能,增强免疫功能,其中以0.2%的添加剂量较好.     

公犬性功能障碍的原因及防制措施

公犬性功能障碍通常是指公犬达到配种年龄却不能正常交配的疾病。临床上较为常见,主要有两种症状：一是公犬在与发情母犬接触时不爬跨母犬,阴茎不能勃起,不产生性反射;二是公犬有性欲,但却不能自然交配,需要人工辅助。     

华南地区干、湿料两种不同饲喂方法对肉猪生产性能的影响

<正>养猪业在我国畜牧业生产中占有十分重要的地位,搞好养猪生产对于发展农业经济、改善人民生活、支援国家社会主义建设,均有十分重要的意义。近年来养猪业迅猛发展,如何更快、更好地提高育肥猪生产已经成为研究的热点。所以除选择好的饲料和加强     

利用废菌渣生产单细胞蛋白饲料研究

本文以废菌渣为主要原料,利用酿酒酵母(Saccharomyces cerevisiae)和黑曲霉(Aspergillus niger)两菌株进行混合固态发酵生产单细胞蛋白饲料.通过单因素试验和正交试验确定最佳培养条件.结果表明,各因素对粗蛋白质含量的影响为废菌渣与麸皮的比例>培养时间>氮源>水料比;混茵固态发酵的最佳培养条件为废茵渣80%:麸皮20%,硝酸铵2%.尿素1%,KH2PO4 2%,MgSO4·7H2O 1%,水料比为2.5:1,pH为4,接种量为20%,培养时间为120 h时,此时粗蛋白质含量最高,由发酵前的9.61%提高到23.28%.     

新城疫病毒贵州不同鸡源分离株F基因的克隆与序列分析

应用PCR技术扩增NDV贵州不同鸡源分离株,包括肉鸡源P1株与BY株、蛋鸡源H2株与FW株、七彩山鸡源N98株和越南斗鸡源DQ株的F蛋白基因,将该基因片段分别进行克隆和测序,并与国内外NDV参考株的对应序列进行比较分析。结果表明:6株NDV贵州不同鸡源分离株的F基因长度均为1 662 bp,编码553个氨基酸;分离株间核苷酸同源性为86.9%~99.7%,氨基酸同源性为91.0%~99.3%;与国内外NDV代表株(LaSota株、B1株、F48E9株、CH2000株和TW 2000株)的核苷酸同源性为84.0%~98.9%,氨基酸同源性为87.2%~98.6%;经系统发育进化树分析,DQ株、N98株、P1株和H2株为基因VIId型,而BY株和FW株为基因IX型。这些结果提示贵州省不同鸡群间存在相同NDV毒株感染的可能性,不同年份间NDV毒株发生基因型改变,而近年来贵州省流行的ND疫情主要是由NDV基因VII型引起。     

Molecular characterization and phylogenetic analysis of new Newcastle disease virus isolates from the mainland of China

Seventy-nine velogenic Newcastle disease virus (NDV) isolates were obtained from infected chicken flocks during the outbreaks of Newcastle disease (ND) in various regions of the mainland of China in 2006. The F gene fragment (535 bp, from nt 47 to 581 of the F gene) which codes the main functional region of the F protein was obtained by RT-PCR and sequenced. All sequences obtained in this study have been submitted to GenBank. All the isolates have the motif ¹¹²R-R-Q/R-K/R-R-F¹¹⁷ at the cleavage site of the fusion protein, which is typical of velogenic NDV isolates. For genotyping, a phylogenetic tree based on nucleotides 47–435 of the F gene was constructed, and the 79 isolates could be divided into two genotypes, namely VIId and III. Most of the isolates proved to be of genotype VIId; only two isolates were of genotype III. Genotype VIId NDV has been the predominant pathogen responsible for most Newcastle disease outbreaks in China. The proportion of isolates of genotype VIId NDV shows an increasing trend, according to studies on the molecular epidemiology of NDV in China from 2002 to 2006.     

Phage display identifies an Eastern equine encephalitis virus glycoprotein E2-specific B cell epitope

The present study identified a linear B-cell epitope in the Eastern equine encephalitis virus (EEEV) E2 glycoprotein by screening a phage-displayed random 12-mer peptide library using an EEEV E2 specific monoclonal antibody (mAb) 7C11 and defined L/F-E/R-Y-T-W-G/R-N-H/W-P as the consensus binding motif. A sequence ((321)EGLEYTWGNHPP(332)) encompassing this consensus motif was found in the EEEV E2 glycoprotein and synthesized for further epitope confirmation. Meanwhile, the corresponding epitope peptides in E2 protein of associated alphaviruses were synthesized for specificity identification. Results showed the mAb 7C11 and murine antisera all reacted strongly against the synthesized polypeptide of EEEV antigen complex, but no reaction with Western equine encephalitis virus (WEEV) and Venezuelan equine encephalitis virus (VEEV) was detected. The knowledge and reagents generated in this study may have potential applications in differential diagnosis and the development of epitope-based marker vaccines against EEEV.     

小反刍兽疫疫苗毒株与强毒株的鉴别性荧光RT-PCR检测方法的建立

对GenBank已公布的小反刍兽疫病毒N基因序列进行分析,设计引物与探针,建立PPRV通用型与Ⅱ系疫苗毒特异型二重实时荧光RT-PCR方法,同时建立针对PPRVIV系强毒株的特异型荧光PCR方法。特异性试验和灵敏度试验表明：建立的二重荧光RT-PCR方法可特异性检测PPRV病毒,其HEX信号通道（通用型）和TAMRA信号通道（Ⅱ系疫苗毒特异型）的检测灵敏度分别可达10^1 TCID50/mL和10^2 TCID50／mL,完全满足PPRV的检测要求。用二重荧光RT-PCR方法对西藏采集的14份羊血清样品进行检测,并用建立的Ⅳ系强毒株特异型荧光PCR方法对二重荧光RT-PCR的检测效果进行评估,结果显示,该方法可有效甄别PPRV强毒株和疫苗毒株,避免假阳性结果的出现。     

水貂绿脓杆菌（PASD03株）鞭毛蛋白的提取与分析

本试验以水貂绿脓杆菌PASD03株为研究对象,对其鞭毛蛋白的提取方法进行研究,分别通过酸裂解、差速离心以及酸裂解结合机械振荡三种方法,用（NH4）2SO4盐析来获得鞭毛蛋白,采用垂直板聚丙烯酰胺凝胶电泳（SDS-PAGE）对提取的绿脓杆菌鞭毛蛋白进行分离纯化,并进行电镜鉴定。结果显示：成功分离出水貂绿脓杆菌的鞭毛蛋白,获得了绿脓杆菌鞭毛蛋白的初提液.绿脓杆菌鞭毛蛋白经SDS-PAGE提示纯化的鞭毛蛋白为一条相对分子质量（Mr）为53×103蛋白带,透射电镜（SEM）观察发现该鞭毛蛋白呈丝状。结论：经酸裂解法并结合机械振荡和硫酸铵沉淀法简便、耗时短、纯度高、产量高,适用于绿脓杆菌鞭毛蛋白的提取。     

中草药饲料添加剂“三黄散”对AA肉鸡生产性能的影响

为评定中草药饲料添加剂三黄散对AA肉鸡生产性能的影响,本研究选用1日龄AA肉鸡300只,随机分成2组,每组设3个重复,每重复50只。第一组为对照组,基础日粮+50 mg/kg土霉素;第二组为试验组,基础日粮+1%中草药饲料添加剂三黄散。饲养期为49 d。结果表明:与对照组相比,试验组日增重效果差异不显著(P>0.05),饲料转化率差异不显著(P>0.05),成活率提高1.20%,差异不显著(P>0.05)。