Animal rights group Safe announced yesterday that the single stalls, most often used for pregnant sows, were to be banned from today after being phased out by government legislation.
Farmer Peter Bloem said although he had never used single stalls, pig farmers had been under increased pressure to discontinue use.
''[Production] is down about 2000 baconers [65kg to 85kg pigs] a week,'' Mr Bloem said.
''It definitely has ... had an impact but it's not the end of the world. There are systems in place that more than adequately replace stalls.''
Pigs were able to move around adequately at his farm, he said.
New Zealand Pork chairman Ian Carter said the industry in general had moved away from single stalls but that was affecting farmers and consumers in New Zealand.
''Fifty-seven percent of pig meat consumed in New Zealand is imported and none of it has to meet our animal welfare standards. That's what the consumers should be worried about.''
There were ''robust'' processes in place around pig farms now, Mr Carter said.
''All farmers have had to send a declaration saying that they are compliant [and] there is an audit programme on all our farms.
''If you keep changing legislation ... [people] will just use offshore products.''
Safe head of campaigns Mandy Carter said in a statement the ban was the first step towards protection of sows.
''[Yesterday marked] the last day that pigs will ever have to suffer in the cruel crates, assuming farmers comply with the law.
''Pig farmers are warned: if they do not comply with the ban, we will find out about it.''
Minister for Primary Industries Nathan Guy did not respond for comment yesterday.
