规模化猪场猪伪狂犬病的防控

选取被免临产母猪5头测免疫抗体,从该5头母猪所产的仔猪中每窝选取4头,共20头分成2组,第1组于不同日龄监测母源抗体;第2组(每日龄组2头)分别于不同日龄免疫接种1头份/头,7 d后进行抗体监测。结果仔猪均获得高水平母源抗体,仔猪猪伪狂犬病基因缺失活疫苗(K-61)首免日龄为30日龄。第一扩繁场实行免疫、检测、淘汰、补充猪伪狂犬病阴性后备母猪的净化方案,结果不达标;腾飞猪场采用全场清群方案,结果猪伪狂犬病得到净化。伪狂犬阴性猪群与阳性猪群生产水平比较表明阴性猪群优于阳性猪群;猪伪狂犬病免疫抑制作用对其他病免疫抗体有一定的影响。全场清群方案可能是控制净化猪伪狂犬病比较有效的方法。     

猪伪狂犬病母源抗体衰减规律及适时首免试验

试验采用伪狂犬病gB抗体ELISA试剂盒,分别检测3日龄和1、2、3、4、5、6、7、8、9、10周龄未免疫猪伪狂犬病母源抗体和相应日龄免疫后3周的伪狂犬病gB抗体,以gB抗体阳性率和S/N值分析猪伪狂犬病母源抗体衰减规律和最佳首免时间。结果表明,母猪分娩前1个月免疫伪狂犬病gE基因缺失弱毒苗,所产仔猪能获得高水平的母源抗体;随着仔猪日龄增加,抗体水平逐渐降低,能维持到10周龄。仔猪在5周龄前免疫伪狂犬病疫苗,母源抗体干扰主动免疫,5周龄后免疫抗体水平均有上升;该场仔猪伪狂犬病最佳首免时间为35~42日龄。     

两种猪伪狂犬病毒基因缺失疫苗产前免疫母猪对仔猪抗体水平的影响

试验选择广东某规模化猪场怀孕母猪30头及其所产仔猪30头用进口猪伪狂犬病病毒基因缺失疫苗(B苗)和国产猪伪狂犬病病毒基因缺失疫苗(A苗)进行免疫试验.结果表明:各组母猪产前10 天免疫接种后20～30 d的母猪抗体水平接近或达到峰值,其所产仔猪10～60 d获得的母体抗体恰巧达到最佳.根据母猪产仔时抗体水平及其后代母源抗体维持时间的关系,建议母猪产前20～30 d为猪伪狂犬病病毒加强免疫接种的适宜时间,仔猪60日龄为适宜的首免时间;使用B苗和A苗免疫对母猪产前免疫是必要的,有利于控制带毒母猪猪伪狂犬病病毒野毒的排放,降低感染其他猪只的机会,提高仔猪保护率.     

伪狂犬病免疫净化方案的评价

从一伪狂犬病阴性场选肉仔猪77头,均在2日龄鼻内接种伪狂犬病gE基因缺失弱毒疫苗1头份,免疫前采血,以后每间隔两周采血1次直至18周龄,检测并分析每份血样中的gE和gB抗体。另从一伪狂犬病阴性场选后备母猪50头,于77、147、175日龄肌注伪狂犬病gE基因缺失弱毒疫苗,于40、60、76、91、114、143、161、173、191、226日龄采血,检测并分析每份血样中gB抗体。结果表明,肉仔猪各周龄伪狂犬病野毒抗体(gE)均为阴性,疫苗母源抗体(gB)随日龄的增加而下降,但在114日龄有5头猪gB抗体阳转;免疫伪狂犬病gE基因缺失弱毒疫苗的后备母猪,首免后抗体上升,二免后抗体明显上升、并保持高水平,第3次免疫后抗体较二免后上升不明显。     

妊娠母猪免疫高致病性猪繁殖与呼吸综合征疫苗对仔猪免疫功能的影响

规模化猪场猪繁殖与呼吸综合征病毒（PRRSV）呈持续性感染,给养猪业造成的损失最为严重。部分规模化猪场未实施切实的猪繁殖与呼吸综合征疫苗免疫,呈慢性和潜伏感染,作者现场对妊娠母猪接种高致病性猪繁殖与呼吸综合征（HP-PRRS）减毒活疫苗（TJM-F92株）,旨在从体液免疫、细胞免疫、非特异性免疫功能角度探讨妊娠母猪接种疫苗后对仔猪免疫功能的影响。选取妊娠60 d母猪随机分为A、B 2组,A组母猪接种HP-PRRS减毒活疫苗（TJM-F92株）,B组母猪接种等量生理盐水,2组所产仔猪于10、20、30日龄时检测PRRSV、猪瘟病毒（CSFV）、猪伪狂犬病病毒（PRV） 母源抗体,以MTT法测定外周血T、B淋巴细胞转化率、以琼脂平板法测定血清溶菌酶含量、以Griess试剂法测定NO含量。试验结果表明,妊娠母猪免疫HP-PRRS减毒活疫苗（TJM-F92株）后,其所产10日龄仔猪PRRSV母源抗体水平显著高于对照组仔猪（P＜0.05）,仔猪CSFV阻断抗体极显著增高（P＜0.01）,20日龄仔猪PRV感染抗体显著下降（P＜0.05）;免疫组和对照组所产仔猪的T、B淋巴细胞转化率及NO、溶菌酶含量均无显著差异（P＞0.05）。提示,妊娠母猪免疫HP-PRRS减毒活疫苗（TJM-F92株）,对所产仔猪非特异性免疫功能和T、B免疫功能均无免疫抑制作用,仔猪抗PRRSV母源抗体、抗CSFV阻断抗体均显著增高且PRV感染抗体降低。     

金华猪仔猪猪瘟母源抗体衰减规律初探

仔猪吸吮经猪瘟疫苗免疫的母猪的初乳后,对10头母猪和各所产仔猪中的任意2头在14、21、28、35日龄分别采血,采用正向间接血凝试验检测猪瘟抗体水平,监测母源抗体在仔猪体内的消长规律,以探索金华猪仔猪猪瘟疫苗最佳首免时间;检测母猪抗体水平以探索对仔猪母源抗体的影响。结果发现,仔猪母源抗体水平随着日龄增大而逐级降低,半衰期为17d左右;仔猪母源抗体水平与母猪抗体水平成正比,随着日龄的增加母猪对仔猪母源抗体影响越来越低。     

某规模场仔猪伪狂犬病免疫抗体消长规律初探

为给规模猪场猪伪狂犬病(PR)免疫程序制定提供参考,在贵州省某规模猪场选取3组不同母源抗体背景仔猪群,按照不同的免疫程序进行PR疫苗免疫,然后设置不同的检测时间点,采集猪血清采用ELISA方法进行gE和gB抗体跟踪检测,初步探索仔猪群免疫抗体消长规律。结果显示:在母源gE和gB抗体均为阴性背景下,1日龄初生仔猪活疫苗滴鼻免疫对免疫抗体水平没有影响,15日龄基因缺失疫苗注射免疫后,免疫抗体水平逐渐升高,45日龄基因缺失疫苗加强免疫1个月后,免疫抗体水平达到顶峰,此后逐渐下降,到120日龄时,仍有50%的有效保护率;在gE母源抗体阴性背景下,产前40 d免疫母猪,55日龄进行基因缺失疫苗注射免疫后,仔猪免疫抗体水平持续升高,90日龄时再用基因缺失疫苗加强注射免疫1次,至120日龄免疫抗体水平达到顶峰,150日龄后开始下降,到185日龄时,仍有50%的有效保护率;在母源gE抗体阳性背景下,疫苗免疫不能使仔猪产生有效的免疫保护抗体。结果表明,仔猪母源抗体背景对于仔猪免疫程序的制定具有较大影响,合理的免疫程序要结合母源抗体和免疫抗体检测结果合理制定,并要及时淘汰gE阳性种猪。     

母猪与仔猪PRRS免疫程序的观察与分析

试验旨在观察南堰猪场母猪与仔猪的PRRS免疫程序。选取15日龄乳猪、25~79日龄保育猪、产后15d及产后25d的母猪,采用猪蓝耳病毒ELISA抗体检测法,检测其母源抗体与免疫抗体水平,其中25日龄仔猪的PRRS母源抗体合格率仅41.3%,而接种高致病性猪繁殖与呼吸综合征活疫苗后14d具有可靠保护力。因此,该场仔猪的PRRS免疫程序需要调整,免疫接种时间可提前到15日龄。产后25d的断奶母猪即免疫高致病性猪繁殖与呼吸综合征活疫苗后146d免疫抗体合格率为100%,说明所选用的高致病性猪繁殖与呼吸综合征活疫苗免疫保护期达5个月。因此,采用母猪断奶时接种该疫苗的跟胎免疫法切实可行。     

母猪与仔猪猪瘟免疫程序的观察与分析

实验旨在观察猪场母猪与仔猪猪瘟的免疫程序。在南堰猪场根据其母猪与仔猪的猪瘟免疫程序,选取15日龄乳猪、25~80日龄断奶保育猪、产后15d母猪、产后25d母猪,采用猪瘟病毒间接ELISA抗体检测法,检测其猪瘟母源抗体与免疫抗体水平,其中,母源抗体合格率随着仔猪日龄的增长有下降趋势,但25日龄断奶时仍然高达97.8%,所以仔猪断奶前无需进行猪瘟疫苗的免疫,还可适当推迟猪瘟活疫苗的首免日龄;而仔猪猪瘟苗首免4周时抗体合格率为100%,因此仔猪猪瘟苗二免的间隔时间应大于1个月;母猪在断奶时猪瘟免疫抗体合格率也为100%,说明该母猪断奶时不需要注射猪瘟活疫苗。从检测的母猪与仔猪的猪瘟母源抗体与免疫抗体的合格率来看,母猪、仔猪在猪瘟免疫注射间隔时间上均有待调整。     

猪圆环病毒病疫苗的临床免疫试验

<正>本试验研究通过采用PCV2-ELISA抗体检测试剂盒对一规模化猪场的30头母猪所产整窝仔猪从出生到出栏进行猪圆环病毒抗体跟踪监测,掌握了PCV2抗体的消长变化,发现仔猪母源抗体可以维持至21日龄以上,确定了仔猪圆环病毒疫苗的初免时间为28日龄(1头份),加强免疫时间为49日龄(1头份),从而制定出仔猪圆环病毒病的最佳免疫程序。1材料与方法1.1材料1.1.1试验猪选取乐山市市中区九百洞猪场的30头健康母猪及其所产各个     

伪狂犬病基因缺失疫苗株(SA215)某些生物学特性研究

本试验测定了伪狂犬病ｇＥ－／ｇＩ－／ ＴＫ－／ ＬａｃＺ＋基因缺失疫苗株（ＳＡ２１５）的致细胞病变效应、安全性、免疫原性和免疫期等生物学特性。试验结果显示,该疫苗株能在Ｖｅｒｏ细胞上适应生长,并形成典型的蚀斑。其对１日龄仔猪、怀孕母猪、牛、羊以及家兔安全,无不良接种反应,接种动物不向体外散毒。ＳＡ２１５疫苗接种猪能抵御高剂量（１０７ＰＦＵ）Ｆａ株强毒感染,攻毒后试验猪的发热期、增重受阻天数、散毒滴度均低于Ｂａｒｔｈａ株疫苗接种猪,远远低于对照组猪。ＳＡ２１５接种猪能维持长时间的高水平中和抗体滴度,免疫期可达半年以上。试验结果表明,ＳＡ２１５株是一株安全、免疫原性好、免疫期长的疫苗株。     

猪伪狂犬病病毒gE基因缺失苗免疫试验

为了掌握猪伪狂犬病gE基因缺失疫苗免疫效果,并制定合理的免疫程序,选用国产和进口的猪伪狂犬病gE基因缺失弱毒疫苗,用4种不同的免疫程序,对250头母猪和1000头仔猪进行了免疫试验。试验期间,按比例定时采集免疫猪的血液,用ELISA试剂盒进行抗体检测,证明猪伪狂犬gE基因缺失疫苗,无论国产苗或进口苗都可以产生良好的免疫效果;无论跟胎免疫、1年2次普免,每隔4个月定时免疫,效果均良好。种猪免疫抗体合格率达100%,仔猪49日龄前抗体合格率达100%,75日龄后抗体逐渐降低,120日龄后基本消失。为了使猪体免疫力更强,不给野毒入侵的机会,建议仔猪在首免后,适当时间进行二次加强免疫。而只给公猪、母猪春秋两季免疫,不给仔猪免疫组,仔猪在35日龄后抗体降为阴性,不能抵抗野毒的侵袭,这种免疫方法不宜推广。     

Immunity to Escherichia coli in pigs: Antibody Secretion by the Mammary Gland after Intramammary or Intramuscular Vaccination with an E. coli Vaccine

Indirect hemagglutinating antibody titres in individual gland samples of colostrum and milk from 13 sows were measured. Five of the sows were vaccinated via a mammary gland and five by the intramuscular route with a live formalinised Escherichia coli vaccine and three remained as non-vaccinated controls.

Antibody titres were higher in colostral and milk whey from the vaccinated sows than from non-vaccinated groups. The inoculated gland in the group of sows given vaccine by the intramammary route secreted milk containing markedly more antibodies to the vaccine E. coli strain than did the non-vaccinated glands. Milk from the vaccinated gland did not contain higher titres to heterologous E. coli O antigens than milk from non-vaccinated glands. Serum titres were the same or higher than the titres in colostrum from non-vaccinated glands.

     

Long-term studies on maternal immunity for Aujeszky's disease and classical swine fever in wild boar piglets

The aim of the studies was to fathom the duration and the role of maternal immunity for Aujeszky's disease (AD) and classical swine fever (CSF) in wild boar offspring. In one experiment, two wild boar sows were infected with a low pathogenic pseudorabies virus (PRV) in 1999. A total of 51 offspring was born between 1999 and 2002 and was monitored for PRV maternal antibodies. In a second experiment, the maternal immunity for CSF was analysed. Therefore, a sow was orally vaccinated against CSF using vaccine baits containing the live-attenuated C-strain vaccine. The vaccination took place in January 1999. The sow gave birth to four piglets in 2001 and to two piglets in 2002. With respect to maternal immunity for AD, some piglets reacted positive in the ELISA up to 27-week post-partum while in the neutralization test antibodies were detected up to 15-week post-partum. The calculated half-life of neutralizing antibodies was 21 days. Regarding CSF, the neutralization titres of maternal antibodies dropped continuously reaching values of < or =10 ND50 20-week post-partum. After the 12th week post-partum, most of the sera reacted negative in the ELISA. However, after the third month, low levels of neutralization titres were still detectable. The results are discussed with respect to the epidemiology and control of both diseases in wild boar populations.     

猪伪狂犬病病毒gE基因缺失苗免疫试验

为了掌握猪伪狂犬病gE基因缺失疫苗免疫效果,并制定合理的免疫程序,选用国产和进口的猪伪狂犬病gE基因缺失弱毒疫苗,用4种不同的免疫程序,对250头母猪和1000头仔猪进行了免疫试验。试验期间,按比例定时采集免疫猪的血液,用ELISA试剂盒进行抗体检测,证明猪伪狂犬gE基因缺失疫苗,无论国产苗或进口苗都可以产生良好的免疫效果;无论跟胎免疫、1年2次普免,每隔4个月定时免疫,效果均良好。种猪免疫抗体合格率达100%,仔猪49日龄前抗体合格率达100%,75日龄后抗体逐渐降低,120日龄后基本消失。为了使猪体免疫力更强,不给野毒入侵的机会,建议仔猪在首免后,适当时间进行二次加强免疫。而只给公猪、母猪春秋两季免疫,不给仔猪免疫组,仔猪在35日龄后抗体降为阴性,不能抵抗野毒的侵袭,这种免疫方法不宜推广。     

猪伪狂犬病油乳剂灭活疫苗的制备及安全性与免疫性试验

用本室分离鉴定的猪伪狂犬病毒鄂A经毒株接种仓鼠肾细胞（BHK－21）,制备病毒抗原液，毒价不低于10^-6TCID50/0.1ml。经一定浓度的甲醛溶液灭活后与油相佐剂乳化研制成油乳剂灭活油疫苗4批。本研究对该制品的安全性、免疫性进行了测定。对18g左右小白鼠接种0.3ml，初生仔猪、断奶仔猪及妊娠母猪加倍剂量注射，均未出现不良反应，安全性良好。对母猪的繁殖性能不产生影响。后备母猪及妊娠母清中和抗体指数于免疫后21d达到316以上，间隔35d加强免疫一次后，中和抗体指数可达1000以上。断奶仔猪及初生仔猪免疫后对强毒的攻击，保护率分别为100％及90.62％。     

Safety of an Aujeszky's disease vaccine based on deletion mutant strain 783 which does not express thymidine kinase and glycoprotein I

The safety of an Aujeszky's disease virus vaccine based on strain 783, a deletion mutant which does not express glycoprotein I and thymidine kinase, was assessed in pigs, calves and sheep. Four-day-old piglets which were inoculated intranasally and intramuscularly with 10(7) plaque forming units (PFU) developed only slight depression and fever. The virus was transmitted to a sentinel piglet. Six weeks after inoculation, the pigs were injected with high doses of corticosteroids in an attempt to reactivate the vaccine virus. The pigs did not shed Aujeszky's disease virus, did not develop a rise in virus neutralising antibody titres and sentinel pigs remained seronegative to Aujeszky's disease virus. Strain 783 was passaged in two series of three- to five-day old piglets, but after the third and fourth passages virus could no longer be recovered. Pregnant sows were inoculated with 10(7) PFU of virus strain 783 around day 35 or on day 85 of pregnancy, and their fetuses and piglets were assayed for Aujeszky's disease virus and antibodies against Aujeszky's disease virus. No evidence was found for transplacental transmission of the virus. Calves and sheep were given 10(7) PFU of virus strain 783 intranasally or intramuscularly; they survived and did not develop clinical signs of Aujeszky's disease. All the sheep and the calves inoculated intramuscularly developed neutralising antibodies to Aujeszky's disease virus.     

猪伪狂犬病灭活疫苗(HB-J株)对兔与猪免疫攻毒保护平行关系的研究试验

用研制的连续3批猪伪狂犬病灭活疫苗(HB-J株)分别以不同剂量免疫健康兔和断奶仔猪,检测其免疫28 d后的血清抗体,采用血清中和试验法测定血清中和指数,并对免疫28 d后的兔和断奶仔猪分别进行攻毒,统计各组兔和断奶仔猪免疫后攻毒保护率。结果表明,兔免疫28 d后的血清抗体中和指数为794～1258时保护率为60%～80%,血清抗体中和指数≥1479时可获得100%保护;仔猪免疫28 d后的血清抗体中和指数为229～269时保护率为60%～80%,血清抗体中和指数≥331时可获得100%保护。兔与仔猪对猪伪狂犬病灭活疫苗(HB-J株)均产生良好的免疫应答反应,抗体值较高者获得保护率相对较高,兔与猪免疫与攻毒保护呈现平行关系。     

Long‐Term Studies on Maternal Immunity for Aujeszky's Disease and Classical Swine Fever in Wild Boar Piglets

The aim of the studies was to fathom the duration and the role of maternal immunity for Aujeszky's disease (AD) and classical swine fever (CSF) in wild boar offspring. In one experiment, two wild boar sows were infected with a low pathogenic pseudorabies virus (PRV) in 1999. A total of 51 offspring was born between 1999 and 2002 and was monitored for PRV maternal antibodies. In a second experiment, the maternal immunity for CSF was analysed. Therefore, a sow was orally vaccinated against CSF using vaccine baits containing the live‐attenuated C‐strain vaccine. The vaccination took place in January 1999. The sow gave birth to four piglets in 2001 and to two piglets in 2002. With respect to maternal immunity for AD, some piglets reacted positive in the ELISA up to 27‐week post‐partum while in the neutralization test antibodies were detected up to 15‐week post‐partum. The calculated half‐life of neutralizing antibodies was 21 days. Regarding CSF, the neutralization titres of maternal antibodies dropped continuously reaching values of ≤10 ND₅₀ 20‐week post‐partum. After the 12th week post‐partum, most of the sera reacted negative in the ELISA. However, after the third month, low levels of neutralization titres were still detectable. The results are discussed with respect to the epidemiology and control of both diseases in wild boar populations.     

Maternally-derived antibodies to porcine parvovirus and their effect on active antibody production after vaccination with an inactivated oil-emulsion vaccine

Two sows which had been vaccinated with an oil-emulsion porcine parvovirus vaccine, and had developed high haemagglutination-inhibiting antibody levels to the virus, farrowed three successive litters each, a total of 74 piglets. Serum samples from these piglets were tested for haemagglutination-inhibiting antibody at birth, three and 17 days after birth, and at monthly intervals thereafter to study the decline of maternally-derived antibody. Regression curves were constructed from the data to show the projected pathway (mean and 95 per cent tolerance limits) of the decline of maternally-derived antibody. Approximately half the pigs still had positive titres of up to 1/160 at six months old, and traces of antibody were detected in a few pigs at nine months. Thus, even at the onset of breeding some gilts can have maternally-derived antibody which may interfere with their ability to develop active immunity to porcine parvovirus. From the same litters three groups of 12 pigs were selected randomly and were vaccinated with a single dose of the oil-emulsion vaccine at 70 days, 130 days or 190 days respectively. Despite the presence of moderate to high titres of maternally-derived antibody, especially in the younger pigs, all of those vaccinated showed strong and long lasting antibody responses to the vaccine. High serum antibody titres at the time of vaccination seemed to depress the response to the vaccine slightly but the effect was not statistically significant. These results have important implications for prevention of reproductive failure induced by porcine parvovirus.