Activists have covered the iconic cow statue at Fonterra's Whareroa plant in Taranaki with red paint and hung a "dairy kills" sign from its neck to commemorate Bobby Calf Awareness Day.
Taranaki Animal Save spokesperson Elin Arbez said they took the action on Sunday during the peak of calving season to spark discussion about the plight of bobby calves.
"Despite dairy consumption being ubiquitous in our culture, the grim and deadly truth behind its production remains largely shrouded from public view," she said.
"Statistics from a 2017 Horizon survey found that shockingly, half of New Zealanders surveyed did not know a cow had to give birth to produce milk. More than 80 percent of those asked, vastly underestimated the number of bobby calves killed each year and 60 percent said they felt killing a four-day old calf was unacceptable."
Fonterra said it placed a strong emphasis on animal well-being.
"Fonterra farmers must ensure all non-replacement calves enter a value stream - either beef, calf-veal (bobby) or petfood, and calves are only euthanised on-farm when there are humane reasons for doing so."
Climate Justice Taranaki spokesperson Tuhi-Ao Bailey said dairy farms exported 95 percent of their product overseas, mostly as dehydrated milk powder for processed food.
"The processes for forcing impregnation of cows, removing calves from their mothers and slaughtering them within days is dripping in violence and abuse."
Taranaki Animal Save wanted people to stop consuming dairy products and switch to foods like fruit, vegetables, nuts and grains.