The increasing availability of antibiotics from the mid-1940s was one of the key technological developments which made the factory farming of animals possible. Before that time almost all pigs and poultry, as well as cattle and sheep were kept in free-range systems because it had been found impossible to keep them alive in confined intensive conditions.
As such, it is hardly surprising that almost all intensive livestock production still depends heavily on the use of antibiotics, most of which are administered in feed or drinking water, and are exactly or in some cases closely related to, the antibiotics used in human medicine, including in some cases the antibiotics of last resort. This is despite the statutory ban on all use of antibiotics for growth promotion throughout the EU and the voluntary ban on such use in the US which is being phased in.
This use has two major consequences. First, many foods contain residues of antibiotics. Most of these are below legal levels, though some are not, but little if any consideration is given by regulators to the possible cumulative effect of low levels of different antibiotics in food.
Second, in intensive systems, with very large numbers of pigs or poultry kept together, vets and farmers have little alternative but to administer antibiotics to all animals in a herd or flock, even if only a small number are unwell or suspected of becoming unwell. This is one of the reasons why antibiotic resistance is very high in bacteria found in farm animals and some foods.
But a few medically important antibiotics are also used in horticulture and even sprayed on apples in the US. In addition, recent evidence indicates that some widely-used herbicides, such as glyphosate, can also trigger antibiotic resistance, while antibiotic resistant bacteria on vegetable crops most probably come from the use of river water for irrigation, downstream of either sewage works or factory farms.
All this is contributing to the rise of antibiotic resistance which is becoming a major threat to public health. In the EU an estimated 25,000 people and in the US an estimated 23,000 people already die each year from antibiotic-resistant infections. Yet, we know that in the US 2 million people actually develop a resistant infection each year. Most of these currently recover because a few antibiotics, some of them quite toxic, are still effective in most cases. But this gives an indication of how many people could be at risk of dying if we continue to misuse antibiotics in the way we have been ding. The extra treatment costs and time in hospital are also a huge burden for healthcare systems and for individuals, some of whom are left disabled by the side effects and never fully recover.
Over-use of antibiotics in human medicine, especially over-prescribing by GPs, is believed to cause more direct problems for human medicine than the overuse on farms, but evidence is mounting that antibiotic resistant bacteria from farms transfer to humans in a wide range of ways and contribute to treatment failures in human medicine much more frequently than was previously believed.
The Sustainable Food Trust is a founding member of the Global Alliance to Save Our Antibiotics, and a member of the UK-based Alliance to Save Our Antibiotics. We work to promote farming methods where animals are reared naturally, develop strong immune systems, and there is therefore only minimal need for antibiotics if individuals animals become seriously ill.
Photograph: Farm Sanctuary