4 

 of the metal inducible metalloprotein, metallothionein, in 

 some tissues (Blalock et al . , 1988). 



The bioavailability of inorganic minerals has been 

 measured under different situations for various species (Fox 

 et al., 1981; Wedekind et al . , 1992; Sandoval, 1992) by 

 measuring several factors, such as tissue and fluid mineral 

 concentration, and weight gain. There have been conflicting 

 results concerning the bioavailability of the different Zn and 

 Cu sources . 



