• Antibiotics are commonly added to many types of animal feed.cow image by PinkShot from Fotolia.com
  
  Antibiotics are commonly included in agricultural animal feeds, with their main use being the prevention of disease among animal populations. Ingredient inclusion in animal feeds is a highly regulated process in Canada, and involves the cooperation of federal, provincial and municipal governments. The use of antibiotics in particular is regulated by Health Canada and the Canadian Food Inspection Agency (CFIA).
  
  

Use of Antibiotics

• Antibiotics are used to treat diseases as well as to promote growth.pills image by Andrey Kiselev from Fotolia.com
  
  Antibiotics are primarily used to control the growth of harmful bacteria, which could lead to disease or infection. Infection and disease are easily spread among animal populations living in herds or close quarters, so prevention is of utmost importance. An infection or a full-blown disease could have fatal consequences for the animals. But, an infection is often low-grade and leads to symptoms such as reduced feed and water intake, which can in turn cause slower growth rates. It is common for animal producers to use feeds that contain low levels of antibiotics that treat the types of bacteria to which a particular animal species may be susceptible. This medicated feed can help to control disease outbreak and maintain consistent growth in the animals.
  
  

Human Food Safety Concerns

• Drug residues from the feed can remain in meat, milk and eggs.meat and milk image by Leonid Nyshko from Fotolia.com
  
  One of the main issues with using broad-spectrum antibiotics in animal feed, according to Wiley Interscience, is that residual amounts of the drugs are present in the meats, milk and eggs that humans consume. There is concern that these residues are causing antibiotic resistance among the human population. This concern leads to the difficult question of whether the treatment of human infectious diseases is being weakened by the extensive use of antibiotics in the agricultural industry. Much research has been done in this area, and acceptable residue levels as well as drug withdrawal times (the minimum amount of time needed for the animal to metabolize a specific drug to an acceptable level of tissue residue) have been established, according to the Ontario Ministry of Agriculture Food and Rural Affairs.
  
  

Prevention

• There are several Canadian Acts which help to regulate the use of antibiotics in agricultural animal feed. The Feeds Act prevents the manufacture, sale and import of any feed that may adversely affect the health of Canadian animals or humans. Health Canada creates health safety standards, which are outlined in the Food and Drug Acts and Regulations, and contains information pertaining to veterinary drug use in food-producing animals.
  
  According to the Canadian Food Inspection Agency (CFIA), the drugs permitted for veterinary use must be effective for their purpose, and produce safe results in both the animal and the end product designated for human consumption. These regulations also state that a specified withdrawal period must be used before slaughter and before milk and eggs are sent into the human food chain.
  
  According to Health Canada's Veterinary Drugs Directorate, drug withdrawal times can be found printed on the label of all federally-approved drugs, with the times differing based on whether the end-product is meat or milk, and the type of drug being administered. Meat withdrawal periods can range from 0 to 60 days, whereas milk withdrawal times are usually measured in number of hours (for instance, 48 or 96 hours).
  
  

Enforcement

• Government officials inspect commercial farms, feed mills and meat plants.Red Barn image by rikkidegraz from Fotolia.com
  
  It is the Canadian Food Inspection Agency (CFIA) who administer and enforce the Feeds Act, the Food and Drug Acts and Regulations as well as the Meat Inspection Act. CFIA inspectors regularly visit feed mills and commercial farms to ensure that all feed and drugs are in compliance with both the Feeds Act and the Food and Drug Act, and test for drug residues at federally registered meat plants.