Whole plant black ginger in Escherichia coli-challenged yellow-feather broilers under cold-humid stress: a One Health model for reducing antimicrobial demand

Antimicrobial resistance (AMR) in poultry production is driven by interactions among animal health, antimicrobial use, farm microenvironments, bacterial ecology, and food-chain exposure. This study evaluated whole plant black ginger (Kaempferia parviflora Wall. ex Baker) powder as a locally available phytogenic intervention for yellow-feather Rilai broilers challenged with avian pathogenic Escherichia coli (APEC) under cold-humid stress. A total of 180 one-day-old male chicks were assigned to four treatments, with three replicate pens per treatment and 15 birds per pen: non-challenged control, E. coli-challenged control, antibiotic-treated challenged control, and black-ginger-supplemented challenged birds. Black ginger was provided continuously from day 1 to day 84 at 5 g/kg feed, before and after the day-35 APEC challenge. Compared with the challenged control, black ginger supplementation improved clinical response and feed conversion and reduced cecal E. coli and coliform counts. It also lowered malondialdehyde concentration and was associated with lower end-point abundance of selected AMR genes (blaTEM, tetA, sul1, qnrS, and mcr-1) than in the antibiotic-treated challenged group. However, no pre-treatment AMR baseline, phenotypic resistance testing, or whole resistome analysis was performed; therefore, AMR results should be interpreted as cecal gene-abundance indicators rather than proof of reduced antimicrobial resistance. These findings support black ginger as a promising preventive phytogenic supplement that may improve host resilience under combined climatic and infectious stress, but not as a replacement for veterinary antimicrobial therapy when clinically required.