Fonterra says its 10,500 farmers are well aware the company wants a halt to the practice of inducing premature births of calves in dairy herds to get as many animals as possible milking early in the season.
"We want the practice to cease, farmers are aware of that," Fonterra's general manager of milk supply, Tim Deane, said.
"Fonterra does not support this practice".
Some farmers still call in veterinarians to give late-birthing cows injections of a steroid, Dexamethasone ester, to cause a calf to be born prematurely, bringing the dairy cow back into production two or three months sooner than she would have if left to calve naturally.
Asked why Fonterra did not simply tell its farmers to stop using non-therapeutic inductions, Mr Deane said that with support from an industry body, DairyNZ, the Veterinary Association and Federated Farmers "we are encouraging the remaining farmers still using this practice to phase it out entirely".
Agriculture Minister David Carter this week said allowing dairy farmers to continue a widespread practice of inducing births in milking herds would hurt perceptions in affluent markets offshore.
"There is no doubt that widespread use of induction has the potential to damage New Zealand's reputation, and would be a bad look in today's overseas markets," he said.
The proportion of the national herd being induced had fallen from 9% in 1998 to just over 4% although, because farmers tend to induce only a few of their cows, the proportion of farmers involved is much bigger.
A code of practice to force farmers to better justify the use of the steroid is due to expire. When the code was put in place in March 2006, authorities had expected that by 2010 inductions would be allowed on only 2% of the national herd, limiting it to emergency use.
The Food Safety Authority (FSA) has previously raised questions over animal welfare issues, and whether use of the drug could produce "demonstrable evidence of unnecessary pain or distress".
The National Animal Welfare Advisory Committee (NAWAC) said earlier this year that induction "has the potential to affect the welfare of both cow and calf adversely".
Veterinary Association resource manager Wayne Ricketts said up to 5% of births were induced, and some farmers were "doing quite high numbers, exceeding 20% to 25% of their herd".
"We've set targets for the next three years in individual herds, going from 15% next year, to 8% the following year, then 4%, " Mr Ricketts said.
"We want to phase out the whole thing after that."
From next year every farmer wanting cows induced three to four months before the birth date will first have to consult their vet at least 60 days before the induction visit. The normal gestation period for a calf is nine months.