Reducing antimicrobial usage in small-scale chicken farms in Vietnam: A three-year intervention study

Abstract

Indiscriminate antimicrobial use (AMU) in animal production is a driver of antimicrobial resistance globally, with a need to define sustainable AMU-reducing interventions in small-scale farms typical of low- and middle-income countries. We conducted a before-and-after intervention study on a random sample of small-scale chicken farms in the Vietnamese Mekong Delta from 2016 to 2019. A baseline was established before providing farms (n=102) with veterinary advice on chicken health and husbandry, and antimicrobial replacement products. Thirty-five (34.2%) farms entered the intervention phase; the remainder no longer continued raising chickens. The intervention reduced AMU (-66%) (hazard ratio [HR]=0.34; p=0.002) (baseline 343.4 Animal Daily Doses per 1,000 chicken-days) and mortality (-40%) (HR=0.60; p=0.005) (weekly baseline 1.60 per 100). Chicken bodyweight increased by 100g (p=0.002) in intervention flocks. Our findings demonstrate that in the Vietnamese context, AMU can be substantially reduced in small-scale chicken farms without compromising flock health by providing veterinary advice.