In the past few weeks, the FDA has made two significant announcements regarding the use of antibiotics in livestock.

First: On December 22, it announced that it will end its attempts to restrict the use of penicillin and tetracycline in animal agriculture.

Second: On January 4, it announced a prohibition on the preventive use of another class of antibiotics called cephalosporins, also used to treat illnesses like pneumonia in humans. Â The FDA also prohibits the use of antibiotics not originally designed for use in livestock.

The FDA estimated that 29 million pounds of antibiotics were fed to U.S. livestock in 2009.

Steak With A Side Of Superbugs

Scientists and doctors have repeatedly warned that the use of human antibiotics in livestock encourages the evolution of antibiotic-resistant bacteria.

Because these animals are destined for human dinner tables, these superbugs have a direct route to their future human hosts. They can also infect the people who work with the animals before and during slaughter.

Opponents of the agricultural use of antibiotics point to studies that have found livestock-associated strains of bugs such as salmonella, staphylococcus aureus (which causes staph infections) and E. coli in humans.

Growing Bigger, Stronger, Faster

Livestock farmers supplement their animal feed with antibiotics for two reasons.

First, livestock are usually raised in crowded, closed conditions where infections are easily transmitted from one animal to the next. Preemptive medication helps to stop infections from spreading.

Second, for poorly-understood reasons, antibiotics stimulate growth in young cows and pigs.

The World Organization for Animal Health has said that it would be impossible to raise enough animals to feed the world without the use of antibiotics.

The Journal of Antimicrobial Chemotherapy has argued that more antibiotic-resistant strains have traveled in the opposite direction, from humans to livestock, and that the resistance is actually due to an overuse of antibiotics in humans.

The FDA On Antibiotics: A History

The FDA's desire to regulate antibiotics is grounded in arguments by many scientists that the administering of antibiotics to healthy animals was contributing to the evolution of antibiotic-resistant "superbugs" in both animals and humans.

In the early 1950's, farmers approved the use of small doses of antibiotics as feed additives.

In 1969, a British study proposed that increases in multi-drug resistant illnesses were connected to the use of antibiotics in animal feed. The FDA convened a task force to study that possibility.

For the next forty years, researchers across the United States conducted studies that repeatedly connected the subtherapeutic use (in other words, use on healthy animals) of antibiotics in animal feed to the evolution of antibiotic-resistant bacteria.

The livestock industry, however, repeatedly pointed to different studies that discount the risk of antibiotic-fed meats to human health.

New Legislation Proposed

Since 2009, Congresswoman Louise Slaughter (D-NY) has been working to pass the Preservation of Antibiotics for Medical Treatment Act.

This bill would phase out all preventive uses of antibiotics in livestock and would seek to ensure that all future antibiotics used on animals would undergo rigorous testing before approval.

Farmers would still have the right to treat sick animals with antibiotics.

Read More:

• FDA To Protect Important Class Of Antimicrobial Drugs For Treating Human Illness (FDA)
• News: FDA Won't Act Against Ag Antibiotic Use (Wired)
• Scrooged: FDA Gives Up On Antibiotic Use In Livestock (Grist.org)
• FDA Changing Course On Antibiotics In Livestock (Los Angeles Times)