On the day of the unannounced inspection, they found no evidence of any breaches and the expert considered the pigs to be in good health with no evidence of ill-treatment or neglect.
MPI then viewed footage provided by Farmwatch and noted two pregnant sows in stalls, which breached the Animal Welfare Act.
''The farmer advised MPI that the sows were being kept in the stalls temporarily to manage aggressive behaviour,'' an MPI spokesperson said.
''He also advised some sows were put in stalls after being bullied by other pigs.''
''After their condition had been monitored, they were moved to more suitable areas.''
MPI's manager of compliance investigations, Gary Orr, said the farmer received a formal warning and MPI would not be pursuing further action after considering a number of factors.
''Those factors include that the farmer's actions were motivated by a genuine desire to ensure the animals' overall physical and health needs.
''We also took note of the pig expert's findings that said, overall, the 1500 pigs were being adequately cared for and there were no immediate animal welfare issues.''
Two sows on the farm that housed 1500 pigs were also moved after it was established they were too big for the farrowing crates they were in.
The pig expert concluded that this did not contravene the guidelines of the Animal Welfare Code for pigs but advised, for the pigs' comfort, they should be removed.
The farm now has a designated ''hospital'' pen for animals which need monitoring as well as separate accommodation for sick and injured pigs.
The farmer was provided with advice on how to ensure best practice and compliance with the Act. Mr Orr said the vast majority of people were keen to comply with the law.
''Sometimes we need to provide specific assistance and education, sometimes we need to issue formal warnings.
''Sometimes prosecution is the most appropriate action.
''The action we choose to take is dependent on the facts of each matter and what we consider to be the appropriate method for resolution.''
Mr Orr said that new Animal Welfare (Care and Procedures) Regulations, including regulations governing the welfare of pigs, came into force on October 1. These would make it easier for MPI (and the SPCA) to take action over animal mistreatment.
''New penalties such as fines will be issued for certain actions. We will continue to prosecute the worst offenders under the Animal Welfare Act.''
On July 26, SAFE (Save Animals From Exploitation) ran a Rally for Pigs at Parliament calling for a ban on farrowing crates.
There are about 100 commercial pig farms in New Zealand and an estimated 28,800 breeding sows.
- Central Rural Life