Recently health and environmental concerns were raised after chemicals in the environment originating from certain plastics were observed to have mimicked estrogen . Similar concerns followed the discovery that hormones from pharmaceuticals prescribed for human use survived sewage treatment to be discharged into the environment. Hormones employed by intensive livestock operations present many of the same concerns.

In 2007 Beyond Factory Farming asked the federal government what measures were being taken to study, monitor, and control hormones from intensive livestock production in Canada. Read our Petition, Ecological and human health effects of hormones released into the environment as a result of intensive livestock production in Canada, and the federal government's answers.

Growth hormones

In some cattle operations growth hormone implants are used to increase calves’ growth rate. The use of hormones in cattle has prompted considerable debate concerning the impact of consuming meat with increased hormone levels. Only minute quantities are required for hormone function in the human body, and even slight alterations inquantity can upset the delicate balance with potent physiological effects.

The European Union prohibits imports of meat from animals treated with hormones. Canada failed to meet EU food safety requirements due to free access to veterinary drugs with carcinogenic and/or mutagenic potential, “extra-label use”, and poor residue detection and control systems. The EU position is that the precautionary principle is best, whereas Canada’s stance is that there is a lack of scientific evidence proving hormone use is unsafe. See the full 28 page EU audit.

Hormones permitted in Canadian beef production

Natural Hormones:

  • Progesterone- Naturally occurring reproductive hormone that has been linked to tumours in the reproductive tract of laboratory animals.

  • Testosterone- Reproductive hormone that has been linked to prostate cancer in laboratory animals.

  • Estradiol 17B – This hormone is identified as a “complete carcinogen” (it both promotes and initiates the growth of tumours) and has been linked to shrinking of the thymus gland (which is the center of immune system functioning).

Synthetic Hormones:

  • Trenbolone Acetate (TBA)- This synthetic hormone has been linked to pancreatic and liver tumours as well as hyperplasia.

  • Zeranol- Synthetic hormone linked to testicular abnormalities, pituitary gland tumours

  • Melengestrol Acetate (MGA)- MGA is systematically fed to cattle as a feed additive. It is linked to mammary tumours in female laboratory animals.

Reproductive hormones

In hog operations reproductive hormones are used to control breeding cycles. Hormones such as Swine Somatotropin and beta-agonists are used to speed growth rates during stressful times such as weaning and to control breeding cycles. The EU does not allow for the import of hormone induced pork.