Swedes that have been killing cows in Southland are not the variety sold for human consumption, a Ministry for Primary Industries spokeswoman said yesterday.
The naturally occurring glucosinolates in the HT swedes, the variety believed responsible for killing southern cows, this season appeared to be elevated and threatening animal health, she said.
They did not pose a significant risk to people.
''Just as there are different varieties of apples, there are different varieties of swedes,'' she said.
The swedes were never intended for human consumption.
''It's an animal product. It's just the same as packaging on [food] for dogs. It's not for human consumption.
''While the ingredients may be similar to what humans eat, that particular product was not fit for human consumption.''
There was no evidence to back up claims that the HT (herbicide tolerant) swede had high residual levels of herbicide.
Answering concerns about animal products from stock that had eaten the swede variety, she said a solid body of scientific evidence would show milk or meat from affected animals posed a ''negligible'' risk to people.
At this stage, no public health issues have been reported.
