Production losses associated with natural concomitant infection of Infectious bronchitis virus and Mycoplasma in a broiler breeder farm: A case study

Infectious bronchitis (IB) and mycoplasmosis are two important infectious diseases of poultry that incur significant economic losses to the poultry industry worldwide. Although the infectious bronchitis virus (IBV) and Mycoplasma gallisepticum alone are sufficient to establish a disease and induce significant production losses, the concomitant infection exacerbates and prolongs the severity of the disease. In this study, a total of 25 dead broiler breeder chickens and 100 eggs from a breeder broiler farm in Karnal, Haryana, were examined at the Division of Pathology, ICAR-IVRI, Izatnagar, Uttar Pradesh, in order to ascertain the cause of mortality and production losses. The overall flock strength was about 30,000 birds, and the last three batches had a history of production losses of about 30% in terms of reduced hatchability, early and late embryonic deaths, and defects in external and internal egg quality. Grossly, most cases revealed slight to moderate distension of the oviduct and, at times, a multi-layered amorphous caseous material in the lumen. Cystic oviducts with congested and distorted ovaries were also evident. Microscopically, oviduct lesions include epithelial degeneration, sloughing, necrosis, inflammatory cell infiltrates, tubular glands dilation and lymphoid nodule formation. Molecular analysis by polymerase chain reaction (PCR) was carried out to identify the probable etiology which revealed mixed infection with IBV and mycoplasma as a cause of production losses in the broiler breeder farm.