奶牛副结核病的诊断方法研究

Diagnostic Methods of Paratuberculosis in Dairy Cows

副结核是一种慢性传染性细菌疾病,病原为禽分支杆菌副结核亚种,主要感染牛、羊,造成病畜小肠和其他器官损伤,引发腹泻、体重降低、营养不良、贫血甚至死亡。奶牛副结核病可导致奶牛死淘率增加、产奶量下降、饲料转化率降低、繁殖能力下降、屠宰率降低以及增加其他病原的感染率,从而对奶牛养殖业造成重大的经济损失。副结核分支杆菌主要通过粪口途径进行传播,也可通过子宫进行垂直传播。副结核分支杆菌通过在小肠黏膜下层中的巨噬细胞中持续感染来逃避免疫系统,在大多数情况下,这种隐性感染至少会持续两年,然后细菌开始脱落并出现临床症状。副结核分支杆菌感染进程缓慢,管理不当会使易感犊牛发病率更高,这使得牛副结核病的防控具有很大挑战性,尤其是在季节性产犊牛群中。本文对奶牛副结核病的概念、可造成的经济危害以及诊断方法进行阐述,旨在为奶牛副结核病的临床诊断与新型诊断方法的研制提供参考。

Paratuberculosis is a chronic infectious bacterial disease.The pathogen is Mycobacterium avium subsp.Paratuberculosis,which mainly infects cattle and sheep,causing damage to small intestine and other organs of sick animals,causing diarrhea,weight loss,malnutrition,anemia and even death.Paratuberculosis in dairy cows can lead to an increase in the death rate of dairy cows,a decrease in milk yield,a decrease in feed conversion efficiency,a decrease in reproductive capacity,a decrease in slaughter rate and an increase in the infection rate of other pathogens,thus causing significant economic losses to dairy farming.Mycobacterium paratuberculosis mainly spreads through the faecal-oral route,or vertically through the uterus.Mycobacterium paratuberculosis escapes the immune system by continuously infecting macrophages in the submucosa of the small intestine.In most cases,this recessive persistent infection lasts for at least two years,and then the bacteria begin to fall off and appear clinical symptoms.The slow progress of Mycobacterium paratuberculosis infection and the poor performance of diagnostic test and management system will make susceptible calves infected,which makes the prevention and control of bovine paratuberculosis very challenging,especially in seasonal calves.In this paper,the basic information,economic harm and diagnostic methods of bovine paratuberculosis were introduced,aiming at providing reference for clinical diagnosis and development of new diagnostic methods of bovine paratuberculosis.