46 

 Implications 



Organic sources of Zn (ZnLys and ZnMet) have equal or 

 greater availability than the most available inorganic source 

 (ZnS0 4 ) and may be metabolized differently in some tissues. 

 It is suggested that the highly increased synthesis of MT is 

 proof that ZnLys is a more bioavailable source of Zn. 

 Research is needed to determine if Cu toxicity in sheep can be 

 more effectively suppressed with the use of ZnLys. 



Summary and Conclusions 



A study was conducted to compare supplemental ZnLys, 

 ZnMet, ZnS0 4 , and ZnO on Zn, Cu and MT concentrations in 

 various fluids and tissues of 40 wether lambs. Supplemental 

 Zn (3 60 mg/kg) was fed for 3 wks , withdrawn for 4 wks and then 

 resumed for another wk . Mineral (Zn and Cu) concentrations 

 were determined in serum, liver, pancreas, kidney, bone, bone 

 marrow, hoof, and leg muscle, and only Zn was determined in 

 skin and cornea. Metallothionein content was determined in 

 liver, pancreas and kidney. By d 49 serum Zn had increased 

 less (P < .05) for controls than all but ZnMet, and on d 55 it 

 had increased more (P < .05) for ZnLys than all but ZnS0 4 . 

 There were no treatment effects in serum Cu content, but 

 overall Cu content fell slightly. The ZnLys treatment had the 

 highest (P < .05) Zn accumulation (581, 389, and 340 mg/kg) 

 for kidney, liver and pancreas, respectively. Both ZnS0 4 and 

 ZnMet treatments had higher (P < .05) liver Zn concentrations 



