Animal rights activists say they're horrified 50 pigs have died in a fire at a Waikato farm where 400 died in a similar blaze less than a year ago.
The pigs were among 700 trapped in a piggery that caught fire at Brien Farms in Taupiri, north of Ngaruawahia yesterday morning.
Ten firefighting units managed to keep the flames from spreading from the building to other property nearby but about 50 of the pigs inside died.
No people were reported injured.
The blaze followed another at the same farm in August 2015, in which 400 sows and piglets were killed.
Farm Watch spokesman John Darroch told NZ Newswire concerns had been raised about the heating lamps and wiring at the farm before the current owners took over and he had called for sprinklers to be put in after the last fire.
"Frankly this is a very strong argument against factory farms, aside from other welfare concerns, is just the extreme vulnerability, which you wouldn't see if these animals were able to roam outside," he said.
He said the owners, Ray and Joanne Brien, had said they had only just taken over the farm when the August fire happened and had suggested they would implement changes to avoid repeats.
"They gave the impression they would be doing something to keep it from happening again," he said.
"I'm completely appalled. The mothers are trapped inside these sow crates and they aren't able to turn around, let alone escape from the flames."
In a statement released to media, the Briens said the family and staff were distressed and saddened by the deaths.
They were focusing on supporting their employees and other stock. They would speak further once the fire's cause had been determined.
Another fire killed 300 pigs at the farm in 2005.