Sampling and DNA sample collection
Nasal samples were collected using Performagene LIVESTOCK's nasal swab DNA collection kit (DNA Genotek Inc., Kanata, ON, Canada) from 5 cattle populations-Ambo, Borana, Arsi, Horro, and Danakil-inhabiting different agro-ecologies. Sampling was carried out by considering potential geo-environmental gradients (highland, low-lands), production systems (mixed-crop livestock, pastoral/agro-pastoral), and ethnic groups raising predominantly the populations (Table 1, Fig. 1). Representative sites were selected based upon secondary data obtained from livestock departments and expertise. Herdsmen and owners of the animals were contacted to ensure that the animals were not genetically related. Animals were randomly sampled from multiple herds. Genomic DNA was extracted from nasal samples based on laboratory protocols. In addition, DNA samples from Hanwoo cattle were included for comparison purposes.