Animal antibiotics and science

John Maas is a veterinarian and a faculty member at the UC Davis School of Veterinary Medicine and is the California Cooperative Extension veterinarian for beef cattle.

I read the article “Dead meat” by Terry J. Allen (SN&R Green Days, July 19) with great concern. Allen made many unsupported statements about antibiotic use in livestock production, and as an expert in veterinary medicine and nutrition, I’d like to offer a more fact-based response. We use antibiotics in livestock to treat and prevent diseases, and we do so because we don’t want the animals to suffer. Antibiotics in feed help prevent minor diseases in animals, and this has the added effect of increased growth.

It is important to note that the antibiotics used on livestock are often completely different than those for human use. An example is the use of monensin in cattle feed. Monensin is not an antibiotic, although it does have antibacterial properties and is thus pigeonholed by the U.S. Food and Drug Administration as an antibiotic. The compound acts to increase feed efficiency, decrease methane production (a greenhouse gas) and help prevent problems due to a common intestinal parasite (coccidia). This entire class of drugs has never been used in human medicine, so theoretical resistance is not an issue, and we have never seen resistance in cattle or other species. This is probably the most commonly used compound in livestock that falls under the “antibiotic” label.

Also, resistance to antibiotics is not widely seen in livestock, so the chance of such resistance developing in humans because of livestock antibiotic use is unlikely.

The FDA approves all antibiotic use in livestock, and that approval is based on safety for both animals and people. The federal government (both the FDA and U.S. Department of Agriculture) mandates that no beef with antibiotic residues exceeding FDA standards be allowed in the food supply; all U.S. beef meets these FDA standards. If an animal has been given an antibiotic, that animal goes through a mandatory waiting period while the antibiotics leave the animal’s system.

If an animal is ill, withholding antibiotics to treat the illness can constitute cruelty.

Ranchers and farmers produce different products to meet different needs, and people can buy meat from animals raised without antibiotics if desired; it’s available and it’s their choice. Articles such as this one do a disservice to the public by pushing forward an agenda while neatly circumventing important facts.