Antimicrobials in Chicken Commercial Feeds in Vietnam: A Three-Year Longitudinal Study Before A Nationwide Ban of Growth Promoters
Carrique-Mas J., Cuong NV., Kiet BT., Hien BV., Truong BD., Phu DH., Thwaites G., Choisy M.
Background: Antimicrobial growth promoters (AGPs) are included in commercial animal feed rations in many low- and middle-income countries. We measured antimicrobial use (AMU) in commercial feed products consumed by 338 small-scale chicken flocks in the Mekong Delta of Vietnam, before a nation-wide ban on AGPs which is to be phased in over the coming three years. We reviewed the labels of commercial feeds and calculated amounts of antimicrobial active ingredients (AAIs) given to flocks, highlighting those that did not comply with Government regulations. Results: Thirty five of 99 different antimicrobial-containing feed products (35.3%) included at least one AAI. Eight different AAIs (avilamycin, bacitracin, chlortetracycline, colistin, enramycin, flavomycin, oxytetracycline, virginamycin) belonging to 5 classes were identified. Brooding feeds contained antimicrobials the most (51.2%), followed by grower (34.6%) and finisher feeds (12.5%). The average amount of AAIs given to flocks per kg of chicken at consumption time was 84.8 (SEM ± 9.3 mg). Quantitatively, chlortetracycline was consumed most (42.2 mg/kg SEM ± 0.34; 50.0% of total use), followed by enramycin (18.4 mg SEM ± 0.03, 21.8%) and bacitracin (16.4 mg SEM ± 0.20, 19.4%). Antimicrobials in commercial feeds were more commonly given to flocks in the earlier part of the production cycle. A total of 10 (9.3%) products were not compliant with existing Vietnamese regulation (06/2016/TT-BNNPTNT) either because they included a non-authorised AAI (4), had AAIs over the permitted limits (4), or both (2). Conclusions: and recommendation We found a discrepancy between current legislation and the types and quantities of AGPs found in chicken feeds; this may be a challenge in coming years when the full ban is implemented, and would require that the authorities step up monitoring efforts. Results from this study should encourage discussion about policies on AGPs in low- and middle-income countries.