Gross Tonnage as a measurement does not take into account two very important factors:
- The Potency of the Antibiotic:most of the newer antibiotics commonly used in human medicine are more potent and thus require the use of a lower dose than the older antibiotics commonly used in veterinary medicine. In other words, one ‘therapeutic dose’ of the newer antibiotics commonly used in human medicine weighs less than the equivalent ‘therapeutic dose’ of the older antibiotics commonly used in veterinary medicine. That is why a better comparative figure is the number of therapeutic doses used in each sector.
- Biomass: the dose of an antibiotic is calculated on the bodyweight of the patient, a 650 kg Dairy Cow would therefore need a much larger dose than a 80kg person. Animal numbers also play their part. For instance chickens, although weighing much less, are far more numerous with billions of chickens being produced for consumption in the EU every year. Because of this, milligrams of antibiotic per kilogram of bodyweight (mg/kg bodyweight) is a better measurement of the tonnage used.
According to a recent EU reportstates “ In 18 of 28 countries, the population biomass-corrected consumption was lower or much lower in food-producing animals than in humans, in two countries, the consumption was similar in both groups and in the eight remaining countries, the consumption was higher or much higher in food-producing animals than in humans.”
ECDC/EFSA/EMA second joint report on the integrated analysis of the consumption of antimicrobial agents and occurrence of antimicrobial resistance in bacteria from humans and food-producing animals