In India's English-language media, "chicken" is both singular and plural. Hence this headline in NewstrackIndia.com, for an IANS report datelined Patna:
Hundreds of chicken culled after bird flu outbreak in Bihar. Excerpt:
Hundreds of chicken were culled and large quantity of eggs destroyed in Bihar's Purnea district following an outbreak of avian flu, officials said Saturday.
Purnea district magistrate Manish Verma said the administration had issued bird flu alert as a preventive measure.
"We are fully prepared to deal with an outbreak," he said.
He said bird flu was detected after 300 birds of a government poultry farm died suddenly a few days ago.
"We sent blood samples for test. The results confirmed bird flu," Verma told IANS over telephone.
Verma said he had ordered culling of birds as a precautionary measure to check the spread of the virus.
An official of animal husbandry department said 15 teams of officials have been formed to check the spread of bird flu and ensure that birds and eggs were not send outside Purnea, about 350 km from here.
"All the entry of border along the district have been sealed and additional officials deployed to prevent traders from sending birds outside," an official said.
While the story isn't specific, I think we can assume "bird flu" means high-pathogenic H5N1, which has broken out repeatedly in eastern India in the last few years.