This has doubled the number of chickens needing to be culled, going from 40,000 to 80,000, half the total number of chickens on the farm.
Smith said although it might seem like it, this is not the worst-case scenario for them yet.
“Even though we’ve been promoting this quite heavily, this is not the one that’s spread by migratory birds around the world, which hasn’t arrived in New Zealand yet.
“It’s a serious strain and it’s largely confined to the poultry industry.”
He said there is no indication the H7N6 virus has spread beyond the farm.
MPI said earlier that the laying hens foraging outside were thought to have been infected by wild waterfowl.
A 10km buffer zone had been placed around the farm, along with restrictions to prevent the movement of animals, equipment and feed.
Prime Minister Christopher Luxon said he was informed on Sunday about the case. The farmer understood the risk and had worked closely with MPI to control its spread.
Biosecurity Minister Andrew Hoggard said the farmer had noticed the birds falling ill last Monday on his farm near Moeraki, halfway between Dunedin and Oamaru.
A local vet treated the birds with antibiotics but as more began to die, he notified MPI on Friday.
Testing teams that arrived on Saturday confirmed the positive result for the H7N6 strain. The farm was locked down on Sunday, and testing and tracing of movement continues.
Hoggard said the farm was at the centre of an outbreak of Infectious Bursal Disease Virus Type 1 in 2019.
The virus was discovered in layer hens at the egg farm.
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