White Chick Syndrome Associated with Chicken Astrovirus in Ontario, Canada.

Sixty-four cases of white chick syndrome (WCS) in broiler breeders producing affected progeny were reported from seven hatcheries in Ontario, Canada, between 2009 and 2016, with 43 of those originating from two hatcheries owned by a single company. WCS cases were identified by the presence of typical chicks in the hatchery that were generally weak with pale to white down, enlarged abdomens, and occasionally brown wiry fluff on the dorsum of the neck. Affected embryos and chicks had characteristic gross and histologic liver lesions, and livers were positive for chicken astrovirus (CAstV) RNA by real-time reverse transcriptase PCR. Affected broiler breeder flocks experienced egg production drops of 0% to 21% and hatchability drops of 0% to 68.4%. The amino acid sequence of the region encoding the capsid gene of WCS viruses demonstrated all Ontario CAstV to be in Group B, Subgroup Bii.

Economic Impacts of White Chick Syndrome in Ontario, Canada.

A cluster of 12 cases of White Chick Syndrome (WCS) in broiler breeder flocks producing affected progeny occurred from June to November 2015 in two broiler chicken hatcheries owned by a single company in Ontario, Canada. Cases were identified by the presence of typical chicks in the hatchery characterized by pale to white down, enlarged abdomens, and occasionally brown wiry fluff on the dorsum of the neck that were generally weak. Affected broiler breeder flocks experienced egg production drops of 0% to 15% and hatchability drops of 1.8% to 49.1%. Some flocks experienced increased feed clean-up duration and/or reduced hatching egg weight. The financial impacts of WCS to affected hatching egg producers averaged $5,912 CAD (US$4,417) per 10 000 hens and were as great as $16,788 CAD (US$12,544) per 10 000 hens. The financial impacts of WCS to the affected hatcheries averaged $1,723 CAD (US$1,287) per 10 000 broiler breeder hens and were as great as $4,096 (US$3,060) per 10 000 hens.