All animals commercially slaughtered will need to be stunned first under a new animal welfare code that took effect on Friday.
It is the first time the industry has been made subject to official minimum standards.
The code applies to everyone responsible for the commercial slaughter of animals, including primary processors, home-kill butchers and pet-food makers.
Pre-slaughter stunning has been normal practice in New Zealand meat plants for many years, but there have been exceptions.
One of those has been stock processed to comply with religious practices, in particular to meet Jewish kosher dietary requirements.
Rural butchers providing home-kill services have also been able to slaughter stock without stunning.
No more dropping live crayfish in boiling water
But the chair of the Animal Welfare Advisory Committee, John Hellstrom, says there will be no exceptions from now on.
Dr Hellstrom says the requirement for stunning will also be extended to the slaughter of crustaceans, such as by freezing, so the practice of dropping live crayfish in boiling water will no longer be permitted.
He says the code does not apply to people slaughtering animals on their farms for personal consumption, or to the killing of animals for pest control or recreational hunting.
Agriculture Minister David Carter says consumers requiring meat processed under Jewish shechita dietary laws will now have to import it.
He says about 200 sheep a year were killed under those procedures. Stunning animals before slaughter is accepted in Muslim halal procedures.