1、非洲猪W下的PED防控Prevention and control of PED under ASF12345 背景 Background 材料与方法 Materials and Methods 结果与分析 Results and Analysis 结论与讨论 Discussion 致谢 Acknowledgements背背景景 Background:非洲猪W的发生不仅直接造成猪群存栏的下降，同时也改变了其他主要疾病的防控策略进而影响猪群 的健康。就PED防控来说，在非洲猪W之前已有很多企业通过后备猪的返饲驯化结合灭活苗免疫取得 了良好的防控效果，但在非洲猪W之后考虑到返饲所带来的风险，很多企
2、业不得已放弃了之前成熟的 技术方案，在快速复产及扩群的过程中仍有猪场因PED出现了重大的损失。ASF,not only directly killed pigs but also changed the control strategies of other important swine diseases.Many pig producers had achieved good prevention and control of PED by feedback combined with killed commercial vaccine booster before ASF.Conside
3、ring the risk of feedback under ASF,farms have to abandon the previous mature technical protocol and suffering huge loss due to PED outbreak during rapid repopulation and farm startup.背背景景 Background:非洲猪W发生后我们采用了两种技术方案来进行PED的防控，一种为针对高等级GGP/GP场的以生物安 全为主的野D阴性防控策略，一种为针对大型PS场的后备返饲结合灭活苗免疫的阳性稳定防控策略，两种方案均能
4、有效防控PED，体系内18个种猪场自非洲猪W后未发生过PED。Huanshan adopted two strategies to control PED after ASF occurrence in China.The high level GGP/GP farm focused on biosecurity to keep the farm free of wild virus.The large scale PS farm feedback all the introduced gilts combined with killed commercial vaccine immuniza
5、tion to keep the farm positive stable and wean negative piglets.Both strategies worked well and all the 18 sow farms hadnt experienced PED outbreak since ASF occurrence in China.研究目研究目标标 Objective:非洲猪W后随着行业生物安全的升级也为包括PED在内的主要疾病的净化提供了有利的条件，但多来 源的引种建群扩群也给疾病的防控带来了巨大的风险，通过对体系内高等级GGP/GP野D阴性场的生物 安全的回顾，以及对
6、大量的PS场采用返饲驯化防控的安全性和有效性的研究以期为行业在非洲猪W期 间对PED的防控提供参考。The biosecurity upgrade of the pig industry facilitate the elimination of major swine disease including PED.While the multiple source introduction also brought huge risk to disease control.The report will review the biosecurity protocol used to keep
7、high level GGP/GP farm free of wild virus as well identify the safety and efficacy of the feedback to keep large scale PS farm positive stable.We would like to share the experience to help industry better control PED under ASF.材料与方材料与方法法 Materials and Methods：疫苗免疫组，3个一点式GGP/GP场，基础母猪存栏500-2500头，免疫程序如
8、下：Followed is the control strategy of 3 one stie GGP/GP farm with 500 to 2500 sows返饲驯化组，15个两点式GP/PS场，基础母猪存栏1000-20000头，免疫程序如下：Followed is the control strategy of 15 two site PS farm with 1000 to 20000 sows140日龄前 野D返饲返饲4周后免疫 PED灭活疫苗产前6周PED灭 活苗免疫产前3周PED灭活疫苗免 疫分娩配种161日龄免疫PED灭活 疫苗189日龄免疫PED灭活 疫苗产前3周PED灭
9、活疫苗免 疫分娩配种产前6周PED灭活疫苗免 疫材料与方材料与方法法 Materials and Methods:生物安全管理 Biosecurity复壮仔猪的选择 Piglets for virus amplification返饲驯化组和疫苗免疫组的产房母猪血清及初乳中的抗体水平分析Antibody in serum/colostrum of sows at farrowing in feedback group and vaccination group返饲驯化组与疫苗免疫组后代仔猪攻D保护试验Offspring challenge trials of feedback group and
10、 vaccination group后备母猪返饲后的排D时间与实际返场间隔时间Virus shedding after feedback and the actual interval between feedback and entryPED返饲经济分析Economic analysis of PED feedback结果与分结果与分析析Results and Analysis:生物安全管理Biosecurity：车辆洗消 Truck wash&disinfection 人员隔离 Downtime 物资中转 Transit warehouse 饲料85高温制粒 Feed 85 pellet
11、正压空气过滤 Positive air filtration引自Dr.Dale Polson三个正压空气过滤的一点式GGP场通过科学的生物安全体系实现了猪群的蓝耳抗原抗体双阴，伪 狂犬野D阴性，PED野D阴性3 one-site positive air filtration GGP farm maintain free of PRRSv,gE antibody negative,PED wild virus negative by scientific biosecurity management.结果与分结果与分析析Results and Analysis:结果与分结果与分析析Result
12、s and Analysis:复壮仔猪的选择 Piglets for virus amplification：疫苗免疫组的3-5日龄高健康仔猪 3-5 day suckling piglets from high health GGP/GP farm血清分子学诊断结果 Followed is the health status by serological and molecular test：表表1,1,复壮仔猪使用前的检测结复壮仔猪使用前的检测结果果-表示阴性.means negative检测项目样品类型是否合样检测方法检测结果PRRSV-Ab血清否ELISA-PRRSV-Ag血清是qRT
13、-PCR-PRV-gE血清否ELISA-CSF-Ag血清是qRT-PCR-PCV-2-Ag血清是qRT-PCR-PCV-3-Ag血清是qRT-PCR-ASF-Ab血清否ELISA-ASF-Ag血清是qRT-PCR-APP-Ab血清否ELISA-结果与分结果与分析析Results and Analysis:复壮仔猪的选择 Piglets for virus amplification：病理诊断 Histopathology：未见明显病理损伤No obvious pathological lesion结果与分结果与分析析Results and Analysis:测序显示用于后备返饲的扩增病料和返饲
14、后在后备猪群中检测到的病D为同一D株。与HBJZ2株、LNyk1-2015株亲缘关系最近，同源性为99.4%，表明体系中用于返饲的D株为变异流行D株。Sequence showed the virus used for feedback and virus shed by gilts were same strain.It shaers 99.4%homology with HBJZ2 and LNyk1-2015 which means it belongs to variant epidemic strain in China.基于s1基因遗传进化分析Phylogenetic tree b
15、ased on s1 genes基于s1基因的核酸同源性分析Homology analysis on nucleotides of s1 genes结果与分结果与分析析Results and Analysis:未发现母猪血清IgG与初乳IgA的相关性，提示检测母猪血清IgG可能无法作为PEDv保护力的判断指标。There is no correlation between IgA in colostrum and IgG in serum,indicate that the IgG in serum may not indicate the protectivity of PEDv.IgG a
16、nd IgA S/P Ratio返饲组母猪血清IgG和初乳IgA水平43.532.521.510.50123456789 10 11 12 13 14 15 16 17 18 19 20 21 22 23初乳IgA血清IgG初乳IgA血清IgG结果与分结果与分析析Results and Analysis:未发现母猪血清IgG与初乳IgG的相关性。There is no correlation between IgG in colostrum and IgG in serum.IgG S/P Ratio返饲驯化组母猪血清IgG和初乳IgG水平3.532.521.510.50123456789 1
17、0 11 12 13 14 15 16 17 18 19 20 21 22 23血清IgG初乳IgG结果与分析结果与分析ResultsResults andand Analysis:Analysis:结果与分结果与分析析Results and Analysis:返饲驯化组的母猪初乳中的IgA显著高于疫苗免疫组的母猪初乳中的IgA。The IgA in colostrum of feedback group was significantly higher than vaccination group.返饲驯化组的母猪初乳中的IgG与疫苗免疫组的母猪初乳中的IgG无显著差异。There is n
18、o significant difference of IgG in colostrum between feedback group and vaccination group.提示可以选取母猪初乳中的IgA而不是初乳中的IgG作为PEDv保护力的评估指标。The IgA in colostrum rather than IgG in colostrum may indicate the protectivity of PEDv.返饲驯化组返饲驯化组疫苗免疫组疫苗免疫组P ValueP Value母猪初乳中PEDv IgA2.950.790.700.440.0001母猪初乳中PEDv IgG
19、0.700.710.570.530.7241表表2,返饲驯化组与疫苗免疫组母猪初乳返饲驯化组与疫苗免疫组母猪初乳IgA和和IgGt统计分析统计分析结果与分结果与分析析Results and Analysis:选取23头返饲驯化组的母猪检测分娩后72小时内的乳汁中IgA，未发现返饲后母猪初乳IgA随胎次升高出现下降，可 能与灭活苗的跟胎免疫有关。The colostrum of 23 sows from feedback group were tested for IgA within 72 hours after farrowing.The IgA didnt decline signific
20、antly by parity increase.The pre farrowing killed vaccination may help maintain the IgA.结果与分结果与分析析 Results and Analysis:0 01 13 32 24 41212小时小时2424小时小时6060小时小时攻攻D D后累计的腹泻数量后累计的腹泻数量(10(104 4copies/ml copies/ml)The amount of diarrhea accumulated after challenge疫苗组累计腹泻数量3636小时小时4848小时小时野D驯化组累计腹泻数量从返饲驯化
21、组和疫苗免疫组各选择4头5日龄吃过初乳的仔猪进行攻D，结果显示返饲驯化组的4头仔猪均未 出现腹泻，肛拭子检测PEDv阴性；疫苗免疫组的3头仔猪出现腹泻，4头仔猪肛拭子检测PEDv均为阳性。5 day piglets from both group with adequate colostrum ingestion were challenged with PEDv.None of the 4 piglets from feedback group showed diarrhea,rectal swabs were negative for PEDv.3 of 4 piglets from va
22、ccinated group showed diarrhea,all rectal swabs were positive for PEDv.+表示出现腹泻或检测阳性；-表示未出现腹泻或检测阴性.仔猪编号腹泻qRT-PCRCT value腹泻qRT-PCRCT value1-+22.322-+21.093-+24.734-+19.32表表3,使用使用104拷贝拷贝/ml病病D D液攻液攻D D后的临床表现和肛拭子检测结果后的临床表现和肛拭子检测结果返饲驯化组疫苗免疫组结果与分结果与分析析Results and Analysis:返饲驯化组Feedback Group疫苗免疫组Vaccinati
23、on Group十二指肠Duodenum空肠Jejunum回肠Ileum攻D48小时后收集肠道固定样本进行组 织病理学观察。Full set intestinal fixed samples were collected for histopathological check 48 hours after virus challenge.返饲驯化组十二指肠，空肠，回肠形态正常，未见明显的病D性肠炎损伤。The duodenum,jejunum and ileum of feedback group were normal without obvious viral enteritis lesi
24、on.疫苗免疫组十二指肠，空肠，回肠可见明显萎缩性肠炎，绒毛萎缩变钝，部分 绒毛可见融合The duodenum,jejunum and ileum of vaccinated group showed obvious atrophic enteritis with dull villi and even fused.结果与分结果与分析析Results and Analysis：10090807060504030201001周2周3周6周7周8周PED阳性率4周5周返饲后时间返饲后PED排D监测返饲后每周采集后备猪群的肛拭子进行PEDv抗原监测，发现到第5周时肛拭子为阴性，表示在后备母猪入群前
25、至少需要5 周的排D时间才能保证不会因为引入返饲后的后备猪造成病D扩散。The rectal swap were tested for PEDv weekly after feedback and it turned to negative 5 weeks later.It means the gilts need at least 5 weeks to cool off before enter the main herd to make sure the farm didnt introduce wild virus by gilts introducing.结果与分结果与分析析Resul
26、ts and Analysis：统计2019-2020年共86个返饲返场批次猪群，显示最短的返饲返场间隔时间为5周，平均间隔时间为15周，后备母 猪返饲后有充足的排D时间。提示后备母猪在腹泻停止后仍存在排D。Total 86 batch gilts got feedback and entered farm from 2019 to 2020.The minimum interval between feedback and entry were 5 weeks,the mean interval were 15 weeks which means the gilts had enough t
27、ime to cool off.The gilts may shed virus without diarrhea sign.N=86N=86MeanMeanSDSD腹泻持续时间（天）9.192.51腹泻比率（）91.431.16CT值28.093.64返场间隔时间（天）109440 0 0 01 13384536777721219876543210109 91周2周3周4周5周6周7周8周9周10周11周12周13周14周15周16周17周18周19周20周21周22周23周批次返饲返场间隔时间返饲后返场间隔时间统计表表4,返饲批次统计返饲批次统计经济模型引自Dr.Derald J.Holt
28、kamp基础母猪存栏5,0005,000LSY2.352.25窝均活产11.0011.00年头均断奶仔猪动保成本（￥/断奶仔猪）30.0030.00年断奶仔猪动保成本（￥）3,489,750.003,155,625.00J液，基因费，配种耗材（￥/基础母猪）85.0085.00年配种成本（￥）425,000.00425,000.00生产生产力力正常生产正常生产PED爆发爆发年活产仔猪129,250123,750断奶前死淘率（%）10.0%15.0%窝均断奶窝均年断奶仔猪 年断奶仔猪9.9023.27116,3259.3521.04105,188收收入入每头断奶仔猪价值（￥/头猪）收入（￥/年）
29、1,500.001,500.00174,487,500.00157,781,250.00成成本本固定成本（￥/年）23,000,000.0023,000,000.00可变成本每头基础母猪年耗料（￥/每头母猪）年耗料（￥）3,052.003,052.0015,260,000.0015,260,000.00每头断奶仔猪教槽料耗料（￥/断奶仔猪）年教槽料耗料（￥）年头均基础母猪动保成本（人民币/每头母猪）年基础母猪动保成本（￥）年头均分娩仔猪动保成本（￥/分娩仔猪）年分娩仔猪动保成本（￥）5.005.00581,625.00525,937.50200.00200.001,000,000.001,00
30、0,000.006.006.00775,500.00742,500.0035.00 15.035.00 15.0工资（￥/小时）年头均基础母猪所需劳动时间（小时/基础母猪/年）年人工成本（￥）2,625,000.002,625,000.00100.00100.00其他非饲料可变成本（￥/基础母猪）年其他非饲料可变成本（￥）500,000.00500,000.00总成本总成本（￥/基础母猪）总成本（元总成本（元/断奶仔猪）断奶仔猪）47,656,875.009,531.38409.6947,234,062.509,446.81449.05净利润（￥净利润（￥/年）年）净利润（￥/基础母猪）净利润
31、（￥/断奶仔猪）126,830,625.0025,366.131,090.31110,547,187.5022,109.441,050.95600.0040%85%2,353100返饲成本返饲成本:满产猪群后备入群前返饲满产猪群后备入群前返饲返饲用仔猪成本（￥/头）年更新率后备母猪培育率年需返饲后备母猪头数每头仔猪可返饲后备母猪头数 每头后备母猪需返饲次数返饲用仔猪成本（￥）返饲用仔猪成本（￥）342,352.94返饲操作其他成本（￥）返饲操作其他成本（￥）45,000.00投入产出比投入产出比：一年发生一次PED时 两年发生一次PED时18693600.0085%5,882100返饲成本返饲
32、成本:新场建群后备入群前返饲新场建群后备入群前返饲返饲用仔猪成本（￥/头）后备母猪培育率年需返饲后备母猪头数每头仔猪可返饲后备母猪头数 每头后备母猪需返饲次数返饲用仔猪成本（￥）返饲用仔猪成本（￥）3105,882.35返饲操作其他成本（￥）返饲操作其他成本（￥）115,000.00投入产出比投入产出比：一年发生一次PED时 两年发生一次PED时7437PED返饲经济分析Economic analysis of PED feedback结论与讨结论与讨论论Discussion：1.在非洲猪W感染压力下，严格管控车辆洗消，饲料85高温制粒，选址良好或配备正压空 气过滤的高等级场维持PEDv野D阴
33、性是可行的Its feasible to maintain the high level farm free of PEDv wild virus with good location or positive air filtration through strict truck wash and 85 feed pellet processing under ASF.2.在非洲猪W感染压力下，严格的现场管控，PED的返饲是安全的，不会增加感染非洲猪W 的风险Its safe to feedback the gilts with strict on-site management withou
34、t increasing the ASF infectionrisk.结论与讨结论与讨论论Discussion：3.PEDv返饲能够有效的激活肠道乳腺sIgA轴，结合灭活苗免疫可以有效防控PED的发生 PEDv feedback can activate the gut-mammary gland-secretory IgA axis combined with killed vaccine to effectively prevent PED outbreak.4.母猪初乳中的IgA水平比初乳中的IgG及血清中的IgG更能反映猪只针对PEDv的保护力 The IgA in colostrum rather than IgG in colostrum or IgG in serum indicate the protectivity against PEDv.5.使用产房仔猪复壮病料对后备猪返饲的经济回报是可观的The economic analysis showed the cost benefit of PEDv feedback is considerable.
