GSTM1 and anemia (phenotype): Calves were diagnosed with anemia based on values of the erythrogram; the disorder was characterized by a red blood cell (RBC) count, hemoglobin (Hb) concentration, and hematocrit (Ht) value lower than 5.0 × 106/μL, 8.0 g/dL, and 24%, respectively, as recommended in the literature [24].