64 

 known if Zn and Cu will interfere with each other if they are 

 provided in complexed rather than inorganic forms . 



The purpose of this study was to compare bioavailability, 

 interactions and retention of complexed and inorganic sources 

 of Zn and Cu fed to rats. 



Materials and Methods 



Sixty-three male Charles Sprague-Dawley (CD) strain rats 

 (Charles River Breeding Laboratories, Wilmington, MA) weighing 

 71.5 ± 7.3 g (mean ± SEM) were individually housed in 

 suspended, stainless steel cages in an environmentally 

 controlled room with a 12 -h light: dark cycle. 



Rats were individually fed a purified diet and deionized 

 water ad libitum. The purified diet (Research Diets, New 

 Brunswick, NJ) was based on the AIN-76a formulation and 

 contained the ingredients specified in Table 6-1. The 

 purified diet contained .34 and .71 mg/kg of Zn and Cu, 

 respectively. The diet was formulated to be adequate in 

 protein, energy, vitamins, and minerals for this class of rats 

 (NRC, 1978) . 



Different Zn (Zn methionine, ZnMet ; Zn lysine, ZnLys ; Zn 

 sulfate, ZnS0 4 ) and Cu (Cu lysine, CuLys ; Cu sulfate, CuS0 4 ; 

 Cu oxide, CuO) sources were added to the basal diet at 3 

 mg/kg of Zn and 6 mg/kg of Cu to create a 3 X 3 factorial 

 experiment (organic sources from Zinpro Corporation, Edina, 

 MN; inorganic sources from Southeastern Minerals , Bainbridge, 



