49 

 hemolytic crisis, the liver becomes cirrhotic and the kidneys 

 turn very dark, hemoglobin-stained. This crisis eventually 

 leads to the death of the animal within a few days. 



It has been reported that Cu from some organic sources 

 may be more bioavailable than that from inorganic sources. It 

 has also been postulated, however, that the supplementation of 

 a complexed source of copper may retard or even prevent the 

 onset of this toxicosis. Ishmael et al . (1977) proved that 

 the supplementation of copper methionate in subcutaneous 

 injections was not as toxic as Cu Ca EDTA. It was also 

 hypothesized (Ashmead and Jeppsen, 1993) that the toxicity of 

 complexed minerals is lower than salts due to stearically 

 shielding the metals with the amino acids which have bent 

 around the metals as a consequence of forming the bond. 

 Spears et al . (1991) hypothesized that certain trace mineral 

 chelates or complexes may enter different pools in the body 

 than the inorganic forms. This fact alone may make the Cu 

 from Cu lysine (CuLys) more available but not as toxic as 

 CuS0 4 . 



Because of the known information on Cu toxicosis, the 

 tissues to analyze for Cu would include liver and kidney. 

 Serum Cu and Zn and tissue Zn analyses would also be necessary 

 because of the known interactions between these minerals. 



The objective of this study was to compare toxicity of 

 CuLys and CuS0 4 when supplemented at concentrations that would 

 cause a chronic toxicity to sheep. 



