猪圆环病毒2型和3型混合感染引起的母猪繁殖障碍诊治

【目的】寻找引起某猪场母猪屡次配种不孕的原因。【方法】采集母猪饲料槽中正在食用的饲料检测黄曲霉素B₁含量;采集返情母猪的口鼻腔拭子、肛门拭子及血清,使用PCR、RT-PCR方法检测猪圆环病毒2型(Porcine circovirus 2,PCV2)、PCV3、猪伪狂犬病病毒(Pseudorabies virus,PRV)、猪细小病毒(Porcine parvovirus,PPV)、猪繁殖与呼吸综合征病毒(Porcine reproductive and respiratory syndrome virus,PRRSV)、猪瘟病毒(Classic swine fever virus,CSFV);随机剖检13头返情母猪,采集脾脏、淋巴结、脊髓、子宫、卵巢组织检测繁殖障碍性病毒的感染情况;对检测到的PCV2和PCV3部分阳性样品进行ORF2基因序列分析;观察母猪卵巢病理变化情况,汇总分析结果,诊断该场母猪受胎率低、持续返情的原因。【结果】该猪场饲料中黄曲霉素B₁含量为4.5~9.0 μg/kg,均在GB 13078－2017规定的饲料中黄曲霉素B₁允许范围内(＜20 μg/kg)。PCR、RT-PCR结果显示,口鼻腔拭子、肛门拭子和血清的PCV2、PCV3、PRV、PPV、PRRSV、CSFV检测结果均为阴性;13头母猪的PCV2阳性率为69.23%(9/13),PCV3阳性率为38.46%(5/13),PCV2和PCV3混合感染率为30.76%(4/13)。实时荧光定量PCR检测结果显示,PCV2在脊髓中的病毒载量最高,脾脏次之,淋巴结中最少;PCV3在脾脏中病毒载量最高,脊髓次之,卵巢中病毒载量最少。ORF2基因序列分析发现,PCV2为2d亚型,PCV3为3a亚型。卵巢病理切片观察发现,卵泡细胞数量减少,卵泡腔形状不规则、塌陷扁平。【结论】经过诊断确定该场母猪持续返情、屡配不孕的原因是PCV2和PCV3混合感染,进而引起繁殖障碍。根据诊断结果和该场情况,采取全群接种PCV2疫苗,配合全场消毒,加强生物安全防控,成功解决该场母猪繁殖障碍问题,恢复正常生产。

Diagnosis and Treatment of Reproductive Disorders in Sows Caused by Co-infection of PCV2 and PCV3

【Objective】 The purpose of the experiment was to find out the cause of reproductive failure of sows in a pig farm.【Method】 The feed being eaten in the sow feed trough was collect to detect the content of aflatoxin B₁.The oral and nasal swabs,anal swabs and serums of returning sows were collect to detect Porcine circovirus 2 (PCV2),PCV3,Porcine pseudorabies virus (PRV),Porcine parvovirus (PPV),Porcine reproductive and respiratory syndrome virus (PRRSV),Classical swine fever virus (CSFV) by PCR and RT-PCR methods.13 returning sows were randomly dissected,and the spleens,lymph nodes,spinal cords,uterus,ovaries were collected to detect failure virus. ORF2 gene sequence analysis was performed on some positive samples of PCV2 and PCV3. The pathological changes of sows’ ovaries were observed,the results were summarized and analyzed,and the reasons for the low conception rate and continuous estrus return of sows in this farm were diagnosed.【Result】 The content of aflatoxin B₁ in the feed of the pig farm was 4.5-9.0 μg/kg,all within the allowable range of aflatoxin B₁ in feed specified in GB 13078－2017 (＜20 μg/kg).The results of PCR and RT-PCR showed that PCV2,PCV3,PRV,PPV,PRRSV,CSFV in oral and nasal swabs,anal swabs and serums were negative.The positive rate of PCV2 and PCV3 were 69.23% (9/13) and 38.46% (5/13) respectively,and the mixed infection rate of PCV2 and PCV3 was 30.76% (4/13).The results of Real-time quantitative PCR showed that the viral load of PCV2 in spinal cord was the highest,followed by spleen, and the lowest in lymph nodes.The viral load of PCV3 was the highest in spleen,followed by spinal cord,and the lowest in ovary.ORF2 gene sequence analysis showed that PCV2 was subtype 2d and PCV3 was subtype 3a.Ovarian pathological sections showed that the number of follicular cells decreased,and the follicular cavity was irregular,collapsed and flat.【Conclusion】 After diagnosis,it was determined that the main reason for the continuous return to estrus of the sows in this farm was co-infection with PCV2 and PCV3.According to the diagnosis results and the situation of the farm,all of the sows were vaccinated with PCV2 vaccine,meanwhile,the whole farm was disinfected to enhance biosafety prevention.Eventually,the farm achived the normal production.