*2.3. Principal Component Analysis (PCA)*

Principal component analysis (PCA) was performed in PLINK v1.9 and visualized with the R package "ggplot2" [28]. The PCA was performed before the analysis of the runs of homozygosity distribution and showed that the individuals from the Buubei breed were divided into two groups (Buubei\_1 and Buubei\_2). The final sample numbers are shown in Table 2.
