It is now well known that antibiotic use in animal husbandry far exceeds antibiotic use in humans. There is now considerable corporate and individual interest in reducing the use of antibiotics in animal husbandry – see for example McDonald’s (!) which even has a corporate vision for antibiotic stewardship in food animals.

One issue is that current voluntary food labels can be misleading and there are no real international standards – “antibiotic-free” may be taken to mean “free from antibiotic residues”, which is the state of the raw meat products sold in Singapore, thanks to regulations that are enforced by the Agri-Food & Veterinary Authority of Singapore (AVA). “Raised without antibiotics” is a more precise label, which means that animals were not exposed to antibiotics during any point of their production. This is difficult to achieve (when animals fall ill with bacterial diseases, they should get antibiotic treatment), particularly in most farms in Asian countries, but rising consumer demand has driven this forward more than any government or WHO/FAO/OIE intervention.

I was quite intrigued by A/Prof Direk Limmathurotsukal’s (he is head of microbiology at the Mahidol-Oxford Tropical Medicine Research Unit based in Bangkok) innovative proposal for an even more precise label for meat products – the antibiotic footprint. Based on the carbon footprint concept, his proposal calls for the use of the antibiotic footprint label to communicate the amount of antibiotics used in raising that particular animal. A mock-up picture from A/Prof Limmathurotsukal is shown below of what such a label will look like – for that particular piece of chicken, the antibiotic footprint is 101 mg/kg.


Those figures on the label didn’t come out of thin air. In a remarkable study that was recently published, A/Prof Limmathurotsukal’s team visited 8 farms in rural Thailand and quantified the amount of antibiotics used raising the chickens for one flock (each farm raised between 10,000-28,000 chickens per cycle, with each cycle being 21 or 41 days depending on whether 1-kg or 3-kg chickens were produced). It turned out that raising 1 flock of 14,000 3-kg chickens involved using approximate 4.25 kg of antibiotics. I include the screen capture of the table from the paper below.


For good measure, also screen captured from the paper, here’s what a 1-kg tub of colistin (last-line antibiotic for severe Gram-negative infections in humans) looks like. Just over one tub is used for raising 14,000 chickens.


Here’s a link to A/Prof Limmathurotsukal’s paper again, published in the Bulletin of the WHO.Well worth reading. His estimate is that for chickens raised in Thailand alone (1.4 billion in 2016), a conservative estimate of antibiotics used in one year would be 161 tonnes. I do not know if he will be able to gain sustained corporate support for the use of antibiotic footprint label, but it is certainly innovative and well worth a try. Could adopt it in Singapore too.