The practice of inducing cows to abort their calves so they can start milking earlier will not be permitted from next season.
About a third of dairy farmers use the practice and about three or four percent of cows are induced.
Livestock Improvement Corporation reproduction solutions manager Joyce Voogt said inductions would not be allowed from next spring and that farmers needed to start planning now and develop a year-round proactive approach to reproduction on their farms.
She said farmers needed to focus on increasing their herds' six week in-calf rate.
Ms Voogt said the top 25 percent of farmers were getting a 75 percent six week in-calf rate while the industry average was about 65 percent.