In contrast, introgressed regions contained STAT5A and CSF3, both associated with mastitis resistance in cattle (Usman et al. 2014; Stella et al. 2018), and genes (CX3CR1 and CSF3) and QTLs involved in immune response and parasite resistance (Estrada-Reyes et al. 2022). This evidence concerns the gene CSF3 and mastitis.