0141672 



feed efficiency in sheep with serum zinc concentrations as low as 

 5.24 ppra. All serum values in excess of 7.1 ppm, found in the 

 reviewed literature, were associated with severe toxicity. Puis 

 (1981) reported a 30 to 50 ppm toxic range for this parameter. 



The' toxic hazard level for zinc concentrations in sheep 

 kidney, 185 to 325 ppm, is based in part on the publication of Ott 

 et al . (1966c). Data for sheep liver zinc concentrations indi- 

 cated most values above 185 ppm were associated with toxicity 

 (Table 25). The only exception was a value of 2153 ppm (dry 

 weight) reported by Telford et al. (1982). Puis (1981) reported a 

 toxic concentration for zinc in sheep kidney tissue as 1000 ppm. 

 This concentration would appear too high based on the reviewed 

 1 i ter a ture . 



The 400 ppm toxic hazard level for zinc in sheep liver tissue 

 has been derived largely from the work of Ott et al. (1966c) who 

 found that concentrations near or above this level were associated 

 with toxicosis. Data from the reviewed literature suggest 

 toxicity is not uncommon in the 200 to 400 ppm range for this 

 parameter. All sheep liver zinc levels in excess of 400 ppm, were 

 toxic. No zinc toxicity data for goats were found in the litera- 

 ture reviewed (Table 29). 



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