Genomic DNA was isolated from freshly collected chicken feces according to the previously established protocol [10 (link)]. Fecal samples were transported directly in a sealed box to the laboratory for DNA extraction and were maintained at less than 4°C during transport. The Power Fecal DNA isolation kit (Mo Bio Laboratories, Inc., Hercules, CA, USA) was utilized for DNA extraction, according to the manufacturer’s instructions. The quality of the purified DNA was checked through agarose gel electrophoresis and a UV/Vis Spectrophotometer (Mecasys Co., Ltd., Daejeon, Korea).