It's time to consider whether live chickens should be taken off Hongkongers' shopping list, Leung Chun-ying said yesterday. The chief executive's suggestion - sure to upset those who say birds bought live taste better than chilled or frozen ones - came as 20,000 chickens were being culled after one from the mainland was found with the H7N9 flu virus on Monday. "In the long term, I believe we should review whether we need to maintain the tradition of live chickens," Leung said. Watch: Health officials begin cull of 20,000 poultry at Cheung Sha Wan wholesale market In Pictures: Hong Kong culls live poultry after H7N9 found The government is also considering whether to separate mainland-imported chickens from local birds while they await test results. At present, the two groups are mixed at the Cheung Sha Wan poultry wholesale market, meaning local as well as mainland chickens were included in yesterday's cull at the market. Secretary for Food and Health Dr Ko Wing-man said the government would examine the possibility of finding a venue where the two groups of chickens could be kept apart before sale. This followed a meeting between Ko and local chicken farmers, breeders and traders who demanded such an arrangement. "Imported live chickens should be kept at the border and not transported to the wholesale market until their H7 test results are available," Steven Ho Chun-yin, the legislator representing the agriculture and fisheries sector, said. He said the government's decision to keep them together had caused losses of millions of dollars for local farmers. Leung said finding a site to keep local and imported chickens separate would prove a challenge as the city was short of land. Urging reconsideration of the live-chicken tradition, Leung said it was the fifth time since 1997 that a positive sample of bird flu had been found in Hong Kong. Ko said there would be further threats if the custom of buying live chickens was maintained. He said officials across the border were still tracing the source of the virus detected in the mainland chicken. Sales of live poultry have been suspended for three weeks. Ko said the government was still working out details of compensation for the industry. About 7,000 live chickens are imported from the mainland each day, while more than 13,000 are supplied by Hong Kong farms. Local farmers estimate the industry had prepared at least 300,000 chickens for the Lunar New Year sales peak. Legislator Helena Wong Pik-wan and City University's life sciences programmes director and former government vet Howard Wong Kai-hay said the government should stop importing live poultry from the mainland when there was sufficient local supply. Howard Wong said local health officials could better monitor poultry raising if all chickens on sale were from local farms. Cheng Chin-leung, a chicken farmer in Yuen Long, said his farm currently had 40,000 chicken ready for sale, and they would be too old to be sold at a good price after the three-week ban. He expected to get HK$20 a chicken - 20 per cent of what he could receive for a younger bird during Lunar New Year. So far this month there have been 104 cases of H7N9 on the mainland, 19 of them fatal, according to reports by local authorities. Last year, the mainland had 144 confirmed cases, of which 46 were fatal.