Samples from a smaller free-range poultry farm near Dunedin, that is not owned by Mainland Poultry, are expected today and the farm remains under restrictions.
About 1000 samples have been received for testing at the laboratory at Wallaceville, Upper Hutt.
However, as the wait goes on to see if a second farm has the virus, one conservation biologist said the logistics of free-range farms means they present a huge risk.
Auckland University conservation biologist Dianne Brunton said she would not be surprised if the infection was found there.
“I mean, it’s incredibly contagious and without knowing the details of the farming practice, you know, about who moves where, how eggs are collected and moved around without knowing all of that, you can’t say they’re not connected at this stage.”
Brunton said it could even spread further.
“I wouldn’t be surprised at all if it does get detected at a number of other farms in the region, you know, knowing those connections and those connections can be very, very small connections because it’s so highly contagious.
“So knowing those connections will be kind of the answer to figuring out how this thing is moving around.”
Laying hens foraging outside are thought to have been infected with the H7N6 strain at an Otago farm through a low pathogenic virus from wild waterfowl.
But Brunton said while wild birds can carry the low pathogenic form, free-range poultry farms with large numbers of birds can act like an incubator.
“Free-ranging is great because that takes care of the welfare of the birds, but you’re still concentrating tens of thousands of birds together in quite an unnatural way,” Brunton said.
“And those birds all have fairly low genetic diversity, they are all the same kind of birds, all the same breeds, so that’s a perfect incubator.”
Mainland Poultry, which manages the free-range farm which confirmed NZ's first case of of high pathogenic avian influenza, otherwise known as bird flu. Photo / Ben Tomsett
Mainland Poultry chief executive John McKay said the carcasses, among other things, were being moved to a secure landfill.
“We’re also disposing of all the material on site, so the manure, the leisure, the eggs, the PPE equipment that we have there,” McKay said.
“All of that material is being moved and via secure trucks to a high-security landfill in Southland, so that work is continuing as well.”
MPI director-general Ray Smith appeared before the select committee on Thursday, confident MPI had the resources if bird flu becomes more widespread.
“What I’m pleased about is the way we’ve got ourselves organised, we’ve been able to activate all of our people and we are managing the workload as we need to at the moment.
