Antibiotic Growth Promotion — History and Legacy Welfare Impacts

The decades-long use of subtherapeutic antibiotics in livestock to accelerate growth has left a complex legacy for animal welfare and public health.

Key Facts

Antibiotic growth promotion (AGP) was first discovered in the 1940s and widely adopted by the 1950s
Subtherapeutic doses increased growth rates by 5-10% by altering gut microbiome composition
The EU banned AGP in 2006; the FDA restricted growth promotion claims in 2017
AGP use masked poor welfare conditions — crowded, stressful environments became economically viable
AMR from AGP has contributed to resistance in human pathogens including E. coli and Salmonella

Welfare Considerations

The legacy of AGP on animal welfare is indirect but significant: subtherapeutic antibiotics allowed the intensification of livestock production beyond what animal biology would otherwise tolerate. By suppressing the disease consequences of overcrowding, inadequate sanitation, and chronic stress, AGP enabled production systems that cause substantial welfare harm. The phase-out of AGP is therefore a welfare-positive development, but its full benefit depends on genuinely improving conditions rather than simply substituting therapeutic antibiotic use. Countries that have successfully eliminated AGP with good welfare outcomes demonstrate that this is achievable.

What You Can Do

Choose meat from producers who have eliminated all routine antibiotic use, not just growth promoters
Support regulatory requirements that reduce therapeutic antibiotic use through welfare improvement
Engage with food companies about their antibiotic reduction timelines and welfare improvement plans
Donate to research organizations developing probiotic and management alternatives to AGP
Advocate for One Health frameworks that connect antibiotic stewardship with animal welfare