Precursor-derived in-water peracetic acid impacts on broiler performance, gut microbiota and antimicrobial resistance genes

Past antimicrobial misuse has led to the spread of antimicrobial resistance amongst pathogens, reportedly a major public health threat. Attempts to reduce the spread of antimicrobial resistant (AMR) bacteria are in place worldwide, amongst which finding alternatives to antimicrobials has a pivotal role. Such molecules could be used as “green alternatives” to reduce the bacterial load either by targeting specific bacterial groups or more generically, functioning as biocides when delivered in vivo. In this study, the effect of in-water peracetic acid as a broad-spectrum antibiotic alternative for broilers was assessed via hydrolysis of precursors sodium percarbonate and tetraacetylethylenediamine. Six equidistant peracetic acid levels were tested from 0 to 50ppm using four pens per treatment and 4 birds per pen (i.e., 16 birds per treatment and 96 in total). Peracetic acid was administered daily from day 7 to 14 of age whilst measuring performance parameters and end-point bacterial concentration (qPCR) in crop, jejunum and caeca, as well as crop 16S sequencing. PAA treatment, especially at 20, 30 and 40 ppm, increased body weight at day 14, and feed intake during PAA exposure compared to control (P