6 Things You Should Know About The Use Of Antibiotics On Farm Animals

We’ve written a lot over the years about the overuse of antibiotics in livestock and how this can help create the drug-resistant “superbugs” that sicken millions, and kill thousands, every year — in the U.S. alone. It’s a complicated issue and the solution involves more than just buying the occasional organic chicken from Whole Foods.

A new report [PDF], commissioned by UK Prime Minister David Cameron, highlights not just how pervasive the problem is — involving everything from the manufacture of these drugs through the treatment of animal waste — but how, as things stand now, it’s only going to become an even bigger problem.

Here are just a handful of takeaways from the 44-page report.

There are basically three reasons why farmers give antibiotics to animals. The first, and the one that no one really has any issue with, is treating genuinely ill animals. Which brings up the second reason: “disease prevention.”

The idea here is that because large numbers of animals are kept together in close quarters — and not always in the most sanitary conditions — they need prophylactic doses of antibiotics to preemptively prevent disease from spreading.

That might sound like a thoughtful notion, but research indicates that this low-dose application of antibiotics in healthy animals only makes the situation worse.

The UK report points to a recent study out of China which showed that sub-therapeutic use of antibiotics in pig farming resulted in huge increases in the number of antibiotic resistance genes, when compared to an antibiotic-free site in a similar region.

The third use is growth-promotion. A happy side effect of antibiotic overuse is that it can result in bigger animals, providing farmers with a bigger return on investment. This use of antibiotics in farm animals has been banned in some countries, and the U.S. recently asked drugmakers to voluntarily stop selling antibiotics solely for growth-promotion.

However, only a few drugs were pulled from the market because most growth-promoting drugs are also approved for disease prevention. Likewise, some drug companies continued to brazenly market the pig-fattening effects of their products in spite of the increased scrutiny.

Additionally, the entire growth-promotion benefit may be overinflated. A farmer who raised both traditional and drug-free birds for Perdue recently noted that the chickens without antibiotics all grew to the same required weight as the drugged-up birds. He also noticed no difference in the mortality levels between the two flocks, indicating that no diseases were being prevented by force-feeding antibiotics to chickens.


The UK report acknowledges that because of the lack of transparency on a global basis, it’s difficult to say with certainty exactly how many tons of antibiotics are making their way into animal feed. What does seem to be agreed-upon is that more than 70% of medically important antibiotics in the U.S. are sold for the purpose of providing to livestock, and that this is figure is more than 50% on a worldwide scale.

And their use is only going to become more popular. A 2015 estimate from researchers at the U.S. National Academy of Sciences predicts that global consumption of antibiotics in agriculture will increase by 67% by 2030. Leading that charge will be the BRICS countries (Brazil, Russia, India, China, South Africa) that are emerging as world financial powers.

It’s expected that the increased demand for animal meat (and to a lesser, but still important, extent the consumption of fruits, grains, and vegetables raised using antibiotics) will result in a 99% increase in antibiotic use in these countries over the next fifteen years.


Speaking of China and India, these countries are responsible for supplying many of the active pharmaceutical ingredients (APIs) in these antibiotics. The UK report points to research of API plants in both countries that showed significant levels of these ingredients making their way into the surrounding waste water.

One study of a plant in India found high levels of active ingredients being flushed into a nearby river. The concentration of one common antibiotic was so high that it exceeded the level needed to kill bacteria by 1,000 times.

“To put this in perspective, this means that waste water or effluent in some areas where APIs are released via manufacturing waste have a far higher concentration of antibiotics than you would expect to find in the blood of a patient taking the drug,” reads the UK report.


A 2011 study claims that the overwhelming majority of antibiotics (75-90%) fed to farm animals passes through their digestive systems un-metabolized, meaning that all that cow, pig and chicken poop that hits the ground contains antibiotics.

And it’s not just livestock. The UK report notes the problem that human waste poses to the over-abundance of antibiotics in waste water.

“In countries with less developed sanitation infrastructure, there is a higher risk that waste will not be treated, and sometimes be closer to communities, thus increasing the risks of exposure, the carriage of resistant bacteria by otherwise healthy people, and the rate of drug-resistant community-acquired infections,” reads the report. “It is in these settings that there is an additional concern about antibiotics and resistant bacteria passing into the environment as sewage treatment systems are often not fully functional or do not use appropriate technologies.”


Every time someone calls for increased restriction on antibiotic use in farm animals, the pharma/farm lobbies and their supporters claim that “the science just isn’t there,” but according to the UK report, just about every scientists agrees that this is a problem and limits are needed.

Of the 139 peer-reviewed research papers covering this topic, the UK report says that a mere 7 pieces of academic research argued against the idea of limiting antibiotic use, while 100 academic papers were in favor of limits.


This is not an issue that is limited to one part of the world, nor is a problem that can be solved by only a couple of large countries taking action.

The UK report calls for, among other things, a “global target” for reducing antibiotic use in food production to an agreed-upon level, along with consensus on the restrictions on the use of medically important human antibiotics on animals.

“We believe an ambitious but achievable target for reducing antibiotic use in agriculture is needed, to reduce use over the next 10 years,” reads the report. “There are countries that have advanced farming systems with very low levels of antibiotic use, particularly in Scandinavia. Denmark has combined low use with being one of the largest exporters of pork in the world. Reducing levels of use to that of Denmark for example, an average of less than 50 milligram of antibiotics used a year per kilogram of livestock in the country, may be a good starting point for such a target.”

The researchers believe that this type of decrease can be achieved “without harming the health of animals or the long-term productivity of farmers.”

Steven Roach, Senior Analyst from Keep Antibiotics Working, agrees with this recommendation, which would cut U.S. antibiotic use down to about 1/3 of where it is now.

Congresswoman Louise M. Slaughter, a trained microbiologist and outspoken critic of antbiotic overuse, is applauding the report.

“The continued use of antibiotics in agriculture for nontherapeutic uses such as disease prevention and growth promotion cannot be sustained if we expect antibiotics to continue to be medically effective for humans in the future,” reads a statement from the Congresswoman, who has already introduced legislation to ban the nontherapeutic use of antibiotics in livestock.”Antibiotic resistance is now a global problem which will require a global response.”

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