"There are many more problems than what the death rate is on the actual journey," she said.
A 2015 shipment of 45,000 sheep and 3200 cattle to Mexico from Timaru resulted in just 191 sheep deaths and one cow but she said the whereabouts of the animals could not be traced. She said there was anecdotal evidence many were slaughtered, she said.
"I'm not saying that's what happened to the dairy cows in China but there is a concern about what happens at the other end - in China there is a lot of intensive dairy farms and they could end up being indoors indefinitely.
"What difference does it make if the slaughter happens immediately or when you are past your best? We have to also remember the calves from the cows are also going to be slaughtered in ways that would be illegal and abhorrent to New Zealanders."
She said not all destinations were investigated and Australian investigators reported "truly horrific conditions".
"We are essentially washing our hands of them when they go overseas and then rubbing our hand with glee for the money we get, while not being concerned for the conditions they are being kept in. It is real worry and a lot of people are angry about it and worry it might happen to New Zealand animals."
Federated Farmers Hawke's Bay president Will Foley said farmers had a "total responsibility" for animals beyond the farm gate and their treatment should be at least comparable to New Zealand standards.
"We can't send them on a truck and ship and then forget about them," he said.
Live exports was undesirable but at times a "lucrative option" for farmers, despite the long-term risk to farming, he said.
"I hope the tide turns on shipping breeding sheep - we are losing our flock. We are declining in sheep numbers every year and there will be a point where we lose the benefit of large-scale processing and having a reasonable quantity to market."
Ms Carter said there was also the risk of a consumer backlash.
"It surprises me there isn't more anger from farmers because it is something that directly concerns them."