Piglets are driven onto a transport trailer via a loading ramp (symbol image)
Photo: Countrypixel / IMAGO
Around ten hens are sometimes kept on one square meter – for eggs from barn systems in Germany.
If animals live in too small a space with too many conspecifics, they quickly become ill or the risk of it simply increases.
Therefore, all animals on a farm often receive antibiotics, also prophylactic.
Sometimes also so that they grow faster to a weight ready for slaughter.
This is not without consequences: the widespread use of antibiotics encourages bacteria to develop resistance to the active ingredients.
They then no longer respond to treatment.
This becomes dangerous when bacterial diseases break out among people who can then hardly be treated.
Sometimes multi-resistant pathogens develop against which (almost) all antibiotics are ineffective.
Despite the fear of such resistances, more and more antibiotics will be used in agriculture in the next few years, according to a study in the journal Plos Global Public Health.
Between 2020 and 2030, use will increase by eight percent.
And this despite ongoing efforts to use fewer antibiotics.
Most countries do not publish data
According to estimates by the World Health Organization (WHO), 1.3 million people die every year because antibiotics do not work on their infections.
In hospitals in particular, bacteria often circulate against which hardly any antibiotics are effective.
On meat or eggs, for example, antibiotic-resistant germs can reach people if hygiene standards are not observed in the kitchen.
This includes, for example, heating poultry thoroughly and cleaning cutting boards if raw meat has been handled.
But unnecessary or incorrect use of antibiotics in humans also promotes the development of resistance.
It is difficult to say how many antibiotics individual countries use in animal husbandry.
Most states would not publish accurate data on antibiotic use, study author Thomas Van Boeckel from ETH Zurich told Nature.
Although the World Organization for Animal Health actually records the antibiotic consumption of the countries, around 40 percent of the states would not report this.
Antibiotic hotspots identified
The researchers therefore estimated the use of antibiotics in order to derive a trend up to the year 2030.
It was based on data from 42 countries and projections from the Food and Agriculture Organization of the United Nations.
Using maps showing the density of animals, the specialist team identified geographic hotspots for the use of antibiotics in animal husbandry.
For the year 2020, it determined the use of around 99,500 tons of antimicrobial agents.
By 2030, it is estimated, this number could increase by eight percent to around 107,400 tons.
According to the study, this value is higher than previous projections.
The researchers observed clear regional differences: Most antibiotics are currently used in Asia - especially in China - about 67 percent of the total amount could be accounted for on the continent.
This trend is expected to continue until 2030.
China is followed by Brazil, the US, India and Australia as the frontrunners in antibiotic use.
In contrast, according to the study, less than one percent of the global use of antibiotics is in Africa.
However, experts estimate that the value will increase the most by 2030.
This is due to the increasing demand for meat products on the continent.
However, there are some uncertainties in the analysis.
According to the »Nature« article, Ranya Mulchandani, first author of the study, points out that most of the countries that publish data are high-income countries and are therefore only partially representative.
Antibiotic use in other states remains an estimate.
A global overview of the use of antimicrobial agents is important, the study says.
It could help determine how dependent individual states really are on antibiotics in animal fattening and where containment efforts are particularly needed.