Figure 4: Trace element concentration (A. Co; B: Cu; C: Mn; D: Zn) in whole blood specimens of dairy cows suupplementation with 400 or 200g/d charcoal and 200g charcoal plus 500mL sauerkraut juice (week 1-14), 120g/d humic acids and 100 or 50 mL/d Aquahumin plus 200 and 100g charcoal (week 15-22) and without substitution (week 23-26). A significant increase in Co occurred between 26 weeks and all the other sampling times (P<0.05), Cu significantly increased at 22 and 26 weeks in relation to the starting point (P<0.05), and Zn and Mn were significantly reduced from point 0 in relation to the other sampling periods (P< 0.05), (N= 40).