The Ministry for Primary Industries has defended a decision to send 3000 dead calves to a landfill near Winton.
The calves were slaughtered as part of the Mycoplasma bovis eradication programme.
Agriculture Minister Damien O'Connor, along with ministry officials, appeared before the Primary Production Select Committee yesterday.
The Clutha-Southland MP, National's Hamish Walker, asked Mr O'Connor when he was made aware of the ministry sending the calves to landfill.
Mr O'Connor replied that he did not know the exact date.
"I can't keep on top of every operational decision - indeed I don't expect to. In checking on it, these were calves that were too small to be processed into any viable food and so something had to be done."
MPI director of readiness and response Geoff Gwyn said the 3000 calves were processed first at a plant near Gore.
He said 1200 of those calves had animal welfare issues, so there was no way they would enter the food chain and all other avenues were explored for the remaining 1800 before they were humanely culled.
Mr Walker asked whether an assurance could be given that no more calves would be sent to that landfill.
Mr Gwyn said there would be calves that would have to be disposed of, but they would only go to accredited landfills.
"This is, and I must stress, the absolute last resort - so I can give you that guarantee, what I can't give you is a guarantee we won't do it again."