Investigation on Infectious coryza of layer chicken in Bangladesh with isolation, identification and antibiogram study

Among infectious diseases, infectious coryza is one of the major problems affecting commercial poultry industry in the developing country like Bangladesh. The present study was conducted for isolation, identification and characterization of Haemophilus paragallinarum from layer chicken in Bangladesh. A total of 122 samples (Nasal / tracheal swab, visceral organs like liver, lung, heart)) were collected from from Rangpur (Paragon Poultry Farm ), Takhurgaon (North Egro Poultry Farm) and Dinajpur (Nizam Poultry Farm) districts of Bangladesh during the period from March 2011 to February, 2012 . The samples were collected from suspected birds based on age, sex, breed, temporal and spatial differences for the isolation and identification of Haemophilus paragallinarum by morphology, staining, cultural and biochemical properties. A total of 122 samples were screened by epidemiological study, of which the overall prevalence of Haemophilus paragallinarum was detected as 47.54 %. The prevalence was very high in laying hen (52.8%) and growing birds (42.8) in compare with the prelaying stage (16.6%). The prevalence of Haemophilus paragallinarum in Dinajpur, Rangpur and Thakurgaon were found 86.67%, 25%, and 34.21% respectively. The isolates were resistant to norfloxacin and tylosin. It was evident that amoxycillin and gentamicin can be of better value in the treatment of infectious coryza in layer chickens in Bangladesh.