Bird flu has been found at a poultry farm in North Somercotes – the fourth recorded Lincolnshire case in recent weeks.
The government said all poultry on the site would be “humanely culled” in a bid to contain the highly contagious H5N1 virus.
A 3km (1.86 miles) protection zone and 10km (6.21 miles) surveillance zone was now in place, officials said.
The threat to public health remained low, they added.
Another farm in the area was also affected last week, according to the Local Democracy Reporting Service.