【作者】 王帅；

【导师】 吴长德； 张宏；

【作者基本信息】 沈阳农业大学 ， 动物疫病防控（专业学位）， 2025， 硕士

【摘要】 鸡滑液囊支原体是主要引发鸡关节滑膜炎、腱鞘炎,以及慢性呼吸道疾病,随着病情在鸡群中蔓延,消化系统、骨骼运动系统和生殖系统会接连受到影响。鸡群会出现因采食量锐导致摄入营养不足,进而严重阻碍鸡的生长发育。在生产性能方面,能导致产蛋鸡的产蛋率显著下滑;在骨骼运动方面,鸡会因关节、腱鞘病变,出现跛行,甚至瘫痪。在我国家禽养殖业普遍发生,具有传播速度快,难以清除、常与新城疫、大肠杆菌、沙门氏菌等细菌或病毒混合感染的特点,给养鸡场带来更大的损失,严重影响养殖效益。本研究通过对辽宁某疑似感染鸡滑液囊支原体的肉种鸡场的发病情况调查与分析,结合血清学检测和分子生物学检测以及药敏试验,了解该种肉鸡场滑液囊支原体的感染状况,结合现场制定了科学的防控方案,取得以下成果:1.本研究调查阶段所采集的辽宁某肉种鸡场(未进行滑液囊支原体免疫)600份血液样品,滑液囊支原体抗体的阳性率为29.00%(174/600),其中16周龄鸡群抗体阳性率为27.33%(41/150),29周龄鸡群抗体阳性率为66.67%(100/150),55周龄鸡群抗体阳性率为22.00%(33/150)。该种鸡场滑液囊支原体感染主要集中在16周龄和29周龄鸡群中,29周龄感染更为严重,超过60%,而55周龄3栋鸡舍虽未发现有症状鸡,但血清抗体仍有部分检出阳性,阳性率为22.00%(33/150),属于隐性感染。2.本研究共分离出滑液囊支原体3株,通过对其vlhA基因的PCR扩增,3株样本均成功扩增出372 bp的vlhA基因片段,通过与Gen Bank数据库中下载的相关基因序列比对并进行系统发育分析得出:3株滑液囊支原体高度同源,与KU572344.1、KU572326、KU572324为同一分枝,均属于基因型K型。3.对剖检采样病料进行药敏试验,得出敏感药物有泰万菌素、强力霉素、替米考星、阿奇霉素,对发病鸡舍进行隔离治疗采用泰万菌素和强力霉素交替使用连用5天,取得了很好的效果,发病鸡舍死淘率降低到3‰,回归正常正常鸡群死淘率。后续进行疫苗免疫,二免之后4周龄采样,抗体阳性率均超过95%,二免10周以后采集咽拭子进行滑液囊支原体荧光PCR检测,结果3份为阳性,尽管鸡场已经稳定,但是现场仍能检出滑液囊支原体病原阳性,滑液囊支原体一旦感染,难以清除。4.通过后续实验室检测及结果分析,制定了适合该场的滑液囊支原体防控方案:严格引种监测制度、全进全出饲养管理制度、疫苗接种(两次免疫,产蛋前4周加强免疫)、阶段性使用药物进行预防、加强现场、管理完善实验室监测。更多还原

【Abstract】 Mycoplasma synoviae in chickens mainly causes synovitis of the joints,tenosynovitis,and chronic respiratory diseases in chickens.As the disease spreads within the chicken flock,the digestive system,skeletal motor system,and reproductive system will be successively affected.The chickens in the flock will experience a sharp decrease in feed intake,resulting in insufficient nutrient intake,which in turn seriously hinders the growth and development of the chickens.In terms of production performance,it can lead to a significant decline in the egg production rate of laying hens.In terms of skeletal movement,due to joint and tendon sheath lesions,chickens will show lameness and may even become paralyzed.It commonly occurs in the poultry farming industry in our country,characterized by a fast transmission speed,difficulty in elimination,and often mixed infections with bacteria or viruses such as Newcastle disease,Escherichia coli,and Salmonella,causing greater losses to chicken farms and seriously affecting the breeding efficiency.This study investigated a suspected MS outbreak in a broiler breeder farm in Liaoning.Through serological and molecular detection,vlhA gene evolutionary analysis,and drug sensitivity testing,the infection status was assessed,and a targeted control strategy was implemented.Key findings include:1、Among 600 blood samples collected from non-vaccinated chickens,the MS antibody positive rate was 29.00%(174/600).Positivity rates were 27.33%(41/150)in 16-week-old (16W)flocks,66.67%(100/150)in 29W flocks,and 22.00%(33/150)in 55W flocks,indicating severe infection in 29W flocks and latent infection in 55W flocks.2、Three MS strains were isolated,and their vlhA genes(372 bp)were amplified.Phylogenetic analysis revealed high homology among the strains,clustering with KU572344.1,KU572326,and KU572324(genotype K).3、Drug sensitivity tests identified tylvalosin,doxycycline,tilmicosin,and azithromycin as effective treatments.Alternate use of tylvalosin and doxycycline for 5 days reduced mortality to 3%.Post-vaccination,antibody positivity exceeded 95.00%after the second dose,but MS pathogens were still detected via PCR,confirming persistent infection.4、A comprehensive MS control plan was established,including strict breeding monitoring,all-in/all-out management,vaccination(two doses with a booster 4 weeks pre-laying),phased prophylactic medication,and enhanced farm surveillance.更多还原