What is believed to be New Zealand's largest shipment of live cattle is due to leave Timaru next week for China.
Some 7200 cows will leave the South Canterbury port for the three-week journey.
The Green Party says exporting live animals is cruel and needs to be more tightly controlled.
MP Julie Anne Genter says the current review of the Animal Welfare Act must include stronger restrictions and needs to include considerations about the ongoing welfare of animals in the country importing them.
South Island Dairy Farmers says the protocols in place to ensure the animals' safety have been developed by animal welfare experts.
Managing director Paul Brown said modern ships are equipped with ventilation and watering systems, and the animals are watched continually by veterinarians.
Mr Brown said New Zealand exports about 20,000 live dairy cattle a year.