By Shelley Wright
CANADAS licensing authority, Health Canada, has announced that it will not approve the milk boosting hormone BST for sale in the country.
The decision was based on more than nine years review of the effects of the drug on animal and human safety, and on the recent findings by two independent external committees.
The expert committees, formed last spring, found there were no human health concerns where BST was used in dairy cows. But the animal health issues, with an increased risk of mastitis of up to 25%, of infertility by 18%, and of lameness by up to 50%, convinced Health Canada that the product should not be licensed. The researchers found that the animal health problems and overall reduced body condition in cows treated with BST led to a 20-25% increased risk of culling from the herd.
"With all of this scientific information available, we saw no reason to delay the decision any longer," said Joel Weiner, acting director general for policy, planning and co-ordination with Health Canadas health protection branch.
"The findings of the animal safety committee, when combined with our own assessment, made it quite clear that Health Canada had to reject the request for approval to use BST in Canada, as it presents a sufficient and unacceptable threat to the safety of dairy cows," he said. "The safety of both human and animal health are critical considerations when assessing a new veterinary drug."
The reviews found no significant risk to human safety through ingestion of products from BST-injected animals.
BST was approved for use in the US in 1994, with manufacturers claiming it could increase milk production in lactating cows by 10%-15%.
The EU introduced a moratorium on BST sales in 1993 which expires at the end of this year.
Campaigners hoping to convince the EU to extend its ban will present the findings of the Canadian research to national governments and EU Commission officials.