The SPCA has condemned the mistreatment of bobby calves revealed in new hidden camera footage as deeply disturbing and inhumane.
An investigation has been launched into the footage, taken on dairy farms in the Waikato and Taranaki in August by animal activist group Farmwatch.
It comes after the Ministry for Primary Industries (MPI) introduced new regulations to improve how calves were treated, following previous hidden camera footage released in September last year.
SPCA New Zealand said the handling of the calves for transport to slaughterhouses, including throwing, dropping and dragging, as shown in the footage was not acceptable.
"No animal should be treated in this way, and to think this was done to vulnerable very young calves is deeply disturbing," Acting CEO Andrea Midgen said.
"We were pleased that MPI implemented some of our recommendations to the new Young Calf regulations that came into force in August this year, however it is clear from the footage shown last night that some of the dairying industry still has a very long way to go to improve their animal welfare standards.
"The behaviour seen in the footage is absolutely unacceptable. We still believe there is further urgent need for better processes, procedures, and oversight, and most importantly for workers to understand how to handle these animals humanely."
Last night the Ministry said it was launching an investigation into the new footage, which shows calves being thrown onto the backs of trucks, dropped onto the ground, and dragged along by their legs.
MPI compliance operations manager Gary Orr said the footage warranted a "full investigation".
"Throwing, dropping and dragging calves in the way the video shows is unacceptable.
"The behaviour we have seen is deeply disappointing given that MPI and industry have worked very hard to promote best practice in animal welfare, in every part of the bobby calf supply chain,leading into this bobby calf season.
"We have been actively doing this for some time and, in collaboration with industry, introduced new, strengthened regulations covering the welfare of bobby calves in August this year. The regulations are part of a widespread suite of initiatives including education programmes endorsed and promoted by industry.
"This activity has had some positive benefits and we have seen improved behaviour and handling throughout the season - which makes the actions of the individuals captured on this footage even more disappointing.
"Additional regulations to safeguard the welfare of bobby calves will be introduced prior to bobby calf season next year.
"MPI takes any form of animal abuse seriously. Bobby calf welfare is a matter of collective responsibility and that includes Farmwatch coming to the party and letting us know as soon as they have evidence of ill-treatment.
"When we have evidence of ill-treatment, we investigate thoroughly. If further action is warranted, we will take it."
Farmwatch spokesman John Darroch told Radio New Zealand the footage showed little had changed since the regulation changes.
He said MPI did not need to change regulations to prosecute such abuse.
"This treatment of animals was illegal, and is still illegal under the Animal Welfare Act," he said. "Workers were doing it then, and they're still doing it now."
Darroch told RNZ the abuse was representative of the handling of calves in the industry.
"If it were only a few people doing this, it would be impossible for us to get this footage."
Green Party animal welfare spokeswoman Mojo Mathers said the culture of rough-handling young animals had clearly not changed with more rules.
"The ministry needs to be out there, on the ground, inspecting and checking on the treatment of animals in New Zealand," she said.
"It's time to ensure that MPI is equipped to protect animals, and the reputation of those farmers who are doing a good job, by doing much more proactive monitoring."
She urged the Government to put more resources into farm inspections.
In July, Waikato slaughterman Noel Erickson, 38, was sentenced on animal cruelty charges to 10 months home detention and 200 hours community work.
He had earlier pleaded guilty to 10 charges laid after the earlier Farmwatch hidden camera sting including two of wilfully ill-treating a calf, recklessly ill-treating calves and using blunt force trauma.