Evaluation of animal feeds for the presence of three important antibiotic classes in Bhutan.

Abstract

An alarming rate of emergence of antimicrobial resistance (AMR) globally has urged Bhutan to take firm steps towards antibiotic stewardship through rational use in humans, animals and agriculture. This study aimed to investigate the use of three important antibiotic classes in animal feeds in Bhutan. Thirteen samples were selected randomly from a pool of feed samples submitted by bidders for Annual Animal Feed Tender (fiscal year 2015-2016) of the Department of Livestock. The 13 samples were tested for nitrofurans and their metabolites, tetracyclines and sulphonamides. The objectives of the study were to evaluate the feed samples for the presence of three antibiotic classes and, if present, to understand the level of presence (mg/kg) in terms of AMR emergence and spread in a Bhutanese context. Two feed samples, belonging to Indian Feed Agents, tested positive for oxytetracycline at levels of 0.072mg/kg and 0.037mg/kg, respectively. Compared with the Feed Additive Compendium recommended dose (10-50g/ton) of oxytetracycline for poultry, the levels found in these two feeds were low. Samples testing positive for antibiotics were rejected in the bidding procedure as being medicated at prophylactic levels and could be the cause of emergence and spread of AMR in the country. Although the samples containing antibiotics were rejected by the Department of Livestock for use in government farms, some farmers may still use medicated feeds. Therefore, more screening needs to be conducted to further confirm and to prevent antibiotic abuse in animal feed in Bhutan.