Stevens said he could give customers an absolute assurance the Tegel turkeys in supermarket freezers were safe to eat.
Frozen stock was being used to make up for the shortfall in fresh turkey, he added.
"It's taking a little bit of management. We're a little bit down on production, we think we'll pretty much sneak through," Stevens said.
Tegel, the only turkey supplier in the country that was not free-range, produced 280,000 turkeys a year from 12 sheds on three farms.
The birds were grown in 12-week cycles.
The company has long been criticised by animal rights groups for its factory farming techniques, including the use of antibiotics.
SAFE director Hans Kriek said crowded conditions meant infection and disease spread like wildfire.
"There's no escaping. When something goes wrong, it goes wrong badly," he said.
Philip Crozier of free-range company Crozier was also critical of factory farming techniques.
"They're locked up until the day they die," he said.
After being killed, many turkeys were dipped in a chlorine solution to destroy bacteria, he added.
"They're just about bleaching the birds. People are walking over broken glass to get free-range turkey."
Free-range frozen turkeys were last week selling at similar prices to Tegel's non-free range option.
A Canter Valley 5kg bird was $72 and a 5.5kg Tegel turkey was $65, marked down from $80.
Butchers were selling Crozier turkeys for about $16 a kilogram.
Canter Valley reported wholesale demand had been up this year as Tegel customers, particularly caterers, looked to make up for the supply shortage.
"I understand there is a shortage. We're not clear what the problem is though," the manager said.
Butchers said the tight supply had pushed wholesale prices up.
Some were no longer taking Christmas orders.
