The footage, which aired on TVNZ's Sunday programme on Sunday night, showed rats running over pigs, cramped conditions, and a dead pig lying among the living.
Both the pork industry and the Ministry for Primary Industries have come under fire from animal rights groups, while the Green Party says it highlights the need for an independent Commissioner for Animal Welfare to be established.
New Zealand Pork chairman Ian Carter, a North Otago pig farmer, said the farm was not condoned by the industry and was not typical of a New Zealand commercial pig farm.
It did not meet the industry's expectations for high animal welfare standards or appropriate standards for the production of food.
It was disappointing a farm had dropped below acceptable standards.
NZ Pork was investing ''significant effort and resources'' to reduce the risk of a farm slipping below standard in the future, Mr Carter said.
''While the process of improvement will always be an ongoing one, I am pleased that this farm is not a typical case,'' he said.
NZ Pork did not answer questions about what sort of response it had had since the programme had aired and whether there would be an economic impact on the industry.
A spokeswoman said the industry body understood that few New Zealanders grasped farming operations and standards comprehensively.
How consumers felt and what they wanted was ''vital'' for the industry and that was why it had responded by developing, implementing and continually improving independent auditing to provide increasingly transparent assurances.
Primary Industries Minister Nathan Guy said the vast majority of farmers did a good job of looking after their animals, and there would always be isolated cases ''but this is not representative of the wider pork industry''.
Anyone with concerns over animal welfare should report them immediately to the Ministry for Primary Industries (MPI).
''They take these issues very seriously and there are strict penalties for mistreating animals,'' he said.
Animal welfare law was being strengthened with the Animal Welfare Amendment Bill, before Parliament, which would make legislation more transparent and easier to enforce.
Save Animals From Exploitation (Safe) head of campaigns Mandy Carter said MPI could clearly not be trusted to enforce animal welfare legislation, as it had an ''obvious conflict of interest''.
''They are there to protect the farmers and animal welfare is not taken seriously enough,'' she said.
Green Party animal welfare spokeswoman Mojo Mathers said establishing an independent Commissioner for Animal Welfare was the only impartial way to ensure that economic interests were not put ahead of ''decent'' animal welfare standards.
A statement from MPI said the ministry was disappointed to see the Canterbury farm had ''regressed to the current unsatisfactory state''.
In April last year, following a complaint from Safe, MPI officials, including a vet, inspected the piggery and found it did not meet the minimum standards set out in the Animal Welfare (Pigs) Code of Welfare relating to hygiene and property maintenance.
MPI made several further visits to the farm and, by August, was satisfied that significant improvements had been made and it complied with the minimum standards of the code.
Last Wednesday, TVNZ showed MPI footage allegedly filmed at the property in April this year.
''MPI was concerned, as members of the public will be, at the general conditions of the piggery depicted.''
The ministry was concerned it only now had the information brought to its attention when Safe appeared to have held the footage since April.
MPI was scheduled to revisit the farm in August, as part of its regular monitoring programme, but had brought that forward and visited last week.
While acknowledging the farm was once again in ''poor condition'', the animals were assessed as generally being in good health.
There were no dead animals observed, a building with exposed wiring featured in the footage was no longer in use, and the farmer had recently undertaken vermin control work.
The ministry would revisit the farm to issue an Animal Welfare Act Statement of Direction to make sure the farmer had an auditable process to address hygiene, vermin control and disposal of dead animals.
