Use of Antibiotics and Hormones in Food Animals

Antimicrobials are used in one of four ways:

• To treat disease that is affecting an animal or an entire herd or flock.  This can range from treating an outbreak of diarrhea in a new group of young calves to treating a tooth abscess in a cat.
• To control disease within a larger group of animals. Antimicrobials can be used to reduce the spread of a specific disease from one or more infected animals to the entire herd or flock.
• To prevent disease from developing. This approach, when used under veterinary oversight, can be a responsible and safe way to promote animal health and welfare.  Regardless of the type of livestock farming (e.g. conventional, extensive, grass fed, free run), farm animals are usually housed in groups.  Within groups of animals, or people, there is usually a certain number that will have some form of illness – whether they are showing symptoms yet or not. Typically, for  short periods during times of high stress for an animal (e.g. following transportation, weaning), an antimicrobial can be provided to prevent animals from becoming clinically sick.
• To promote growth. This used to be a common use of antibiotics.  However, in 2014, members of the Canadian Animal Health Institute agreed to approach Health Canada’s Veterinary Drugs Directorate to voluntarily remove production enhancement and/or growth promotion claims from all medically important antimicrobials used in human medicine.  This policy has been in effect  since December 1, 2018.

Hormones are substances that occur naturally in humans, animals, and plants, so there is no such thing as “hormone-free food”. Hormones are needed by the body to regulate bodily functions and behaviour. Hormonal growth promoters are naturally occurring or synthetic products which can be given to animals to enhance their production of natural hormones.

In Canada, hormonal growth promoters are only approved for use in beef production. They have been safely used in beef cattle since the 1960s to direct growth toward muscle, rather than fat, producing leaner beef at a lower cost to consumers by helping cows convert the food they eat into muscle more quickly and easily.. Beef farmers choose to use hormones in beef cattle because they can safely raise their animals using fewer resources, which in turn decreases not only cost, but also their carbon footprint.

There are six hormonal growth promoters approved in Canada for use in beef cattle (three natural and three synthetic).

In some other countries, like the United States of America, a synthetic version of the naturally occurring growth hormone somatotropin is approved for use in dairy cattle to increase milk production. However, this is not permitted in Canada.

Hormonal growth promoters are also not used in the production of pork or poultry in Canada.

No documented harmful or negative effects have ever been reported in people after consuming meat from animals treated with any hormone or hormone-like substances, when used according to the product label. In fact, the use of hormones in some classes of cattle can improve animal welfare by reducing aggressive behaviour.

The use of hormones in livestock production is considered safe by a number of independent, scientific organizations including:

• Health Canada
• US National Institutes of Health
• US Food and Drug Administration
• Joint FAO-WHO Expert Committee on Food Additives