Serology Study of Mycoplasma gallisepticum in Broiler Chickens in Chongqing

摘要

Mycoplasma gallisepticum (MG) is a bacterium that causes Chronic Respiratory Disease (CRD) a highly contagious disease that affects the respiratory system of the chicken leading to reduced egg production. In chickens, infection may be inapparent or result in varying degrees of respiratory distress with slight to marked rales, difficulty breathing, coughing and/or sneezing. Morbidity is high and mortality low in uncomplicated cases. The aim of this study was to determine the prevalence of Mycoplasma gallisepticum infection among chickens residing on chicken farms in Chongqing. To achieve this aim, field visits were made to chicken farms in WanZhou, ChangShou, HeChuan, JiangJing, QianJiang and WuLong. A total of 22 farms were investigated. A total of 1789 sera samples were tested using a commercial ELISA kit. The overall rate of antibody against Mycoplasma gallisepticum prevalnece was 62.62% (568/907) in 2012 and 72.45% (639/882) in 2013. The prevalence rates among broiler chickens from parental breeders, backyard farms and chicken farms were 50.28, 68.51 and 17.5%, respectively in 2012 and 57.89, 78.14 and 20%, respectively in 2013. When the data were evaluated according to season, the seroprevalence rates was 59.08% in the Spring and 65.89% in the Fall in 2012 and 68.96 and 75.65% in 2013. Seroprevalence rates of the anti-Mycoplasma gallisepticum in 2012 and 2013 varied significantly according to the breeding patterns of the animals (p<0.001). These results demonstrated that M. gallisepticum was widely distributed in chicken in Chongqing region and high stocking density and low air temperature may leading to a even more higher infection of M. gallisepticum.