Dairy NZ says it's not possible to ban the induction of dairy calves overnight.
New Zealand's pasture-based dairy farming system relies on cows calving at the right time of year so they're producing milk when spring grass growth occurs.
Later-calving cows are commonly induced to get them back into sync with the rest of the herd, and the premature calves are either born dead or put down.
Many dairy farmers have abandoned the practice, which, if a new agreement between Dairy NZ, veterinarians and Federated Farmers goes to plan, will be phased out in three years' time.
Dairy NZ strategy leader Rick Pridmore says it's a complex issue.
The Veterinary Association says that for herd management and milk production reasons most vets are now opposed to the practice, which the Green Party is calling on the Agriculture Minister to end.
New code of practice in meantime
Animal welfare group SAFE says there was an agreement to ban it by October and it's opposed to allowing farmers further time to phase it out.
Veterinary Association spokesman Wayne Ricketts says, however, that there was no plan for a ban by October, and that the initial aim to phasing out the practice by the end of the year has been revised.
The plan now, he says, is for inductions to be stopped by 2013, apart from those done on animal health grounds.
In the meantime, Mr Ricketts says, a new code of practice will identify farmers using a high number of inductions, and they will be helped to ensure that cows in their herds get pregnant at the beginning of the season, thus avoiding the need for inductions.
Mr Ricketts says that about 40% of dairy farms are still doing inductions, with the number ranging from very low to as high as 25% of calf births in some newer, large-scale herds.
Breeding solutions sought
The livestock genetics company LIC says more dairy farmers are turning to breeding solutions to reduce the use of calf inductions.
One solution, it says, is to reduce the gestation times in later calving cows.
With that in mind, LIC genetics manager Peter Gatley says, the company has been identifying bulls that can produce cattle that have naturally shorter pregnancies.
Mr Gatley says another method of speeding up the pregnancy in late-calving cows is to use the semen from yaks, a breed of ox from central Asia that has a shorter gestation.