82 

 Zn and Cu by evaluating Zn, Cu and MT concentrations of 

 selected tissues and plasma, and if interaction can be reduced 

 by use of different sources. Phase 2 was conducted to compare 

 Cu and Zn retention time after termination of supplementation. 

 Sixty-three male CD rats were randomly assigned to one of nine 

 treatments which were all combinations of three Zn (ZnMet, 

 ZnLys, ZnS0 4 ) and three Cu (CuLys, CuS0 4 , CuO) sources added 

 to the basal diet at 30 mg/kg of Zn and 6 mg/kg of Cu, to 

 create a 3 X 3 factorial experiment. After the 4 wk 

 supplementation phase, 4 randomly selected rats from each 

 treatment were sacrificed (Phase 1) . The remaining rats were 

 fed the purified, unsupplemented diet for an additional week 

 (Phase 2) . Mineral (Zn and Cu) concentrations were determined 

 in plasma, liver, kidney, bone, and muscle and MT content was 

 determined in liver, and kidney. Plasma Cu concentrations 

 were lower (P < .05) for CuO than CuS0 4 and CuLys supplemented 

 rats. Bone Zn concentrations were higher (P < .05) for CuLys 

 than for CuO supplemented rats. In all tissues where Cu was 

 measured, CuO was the lowest (P < .05) available source of Cu. 

 Furthermore, in muscle, CuS0 4 supplemented rats had higher (P 

 < .05) Cu concentrations than CuLys. Kidney MT content 

 followed the same pattern as Cu concentrations with CuO 

 producing the lowest (P < .05) MT concentrations. Plasma Cu 

 concentrations of depleted rats were lower (P < .05) for CuO 

 than CuLys supplemented rats. Kidney Zn concentrations were 

 lower (P < .05) for CuS0 4 than for CuO supplemented rats after 



