Infectious Diseases 2022

Infectious Diseases 2022

Testicular atrophy in broiler breeders

Gallardo et al (2022) Av Dis - https://doi.org/10.1637/21-00108 23 February, 2022

Infectious bronchitis is a respiratory disease of chickens caused by a gammacoronavirus named infectious bronchitis virus (IBV). Infectious bronchitis virus (IBV), a coronavirus of chickens, is one of the major causes of economic losses in the poultry industry. The name of the disease refers to its most frequent clinical manifestation, although it can infect many other epithelial cells, including the kidney, genital organs and many parts of the alimentary tract. A case report published in Av Dis (Jan 2022) report a case of decreased reproductive efficiency due to male infertility in 33- to 38-wk-old broiler breeders. At necropsy, the males presented with urates deposited on the skin around the vent and testicular asymmetry due to marked unilateral atrophy. In addition to the testicular lesions and IBV presence in testes, serum testosterone levels in roosters from the affected flocks were significantly low.
Histopathology revealed lymphocytic epididymitis, epididymal lithiasis, and orchitis. IBV antigen was detected within collecting and efferent ducts of epididymides by immunohistochemistry. IBV strain DMV/1639 was detected by reverse transcription quantitative PCR in pools of testes, oviducts, tracheas, cecal tonsils, and kidneys from a 37-wk-old affected flock. This report shows evidence of the role of IBV in male chicken infertility and highlights the importance of performing molecular surveillance of IBV to monitor vaccine strains and to detect emerging variants that can potentially hinder production.
The reproductive impairment observed in these broiler breeder flocks is likely a consequence of poor fertility in males, and IBV DMV/1639 is one of the possible causative agents of this condition.