Without a single case of bird flu, Singapore slaughtered 540 chickens on Wednesday in a preparedness exercise that included giving the cullers a placebo dose of Tamiflu, REPORTED DPA. Declaring the city-state is operationally ready to handle any outbreak of the disease, the Agri-Food and Veterinry Authority (AVA) conducted "Exercise Gallus IV at a poultry farm in the city-state. "All our personnel, together with external cullers, knew exactly what to do," said Minister of State for National Development Grace Fu. "We are in a very good position to handle the situation when it arises," she added. Fifty cullers from poultry slaughterhouses and cleaning and construction companies acted as a second line of support. The cullers were screened, given the placebo of the drug, and briefed on wearing their personal protection equipment. The 540 retired layer chickens were gassed with carbon dioxide and disposed of, the AVA said. Otherwise they would have been sent to the slaughterhouse. Participants were sprayed and instructed on how to remove their protective gear in the final stage of the exercise - decontamination. The AVA is hoping to draw conclusions within a week on how to improve the drill, which took two months of planning.