41 



TABLE 4-4. Mean Cu levels in tissues of sheep 

 supplemented with four sources of Zn (mg/kg, DMB a ) 



Tissue 



Control 13 



ZnO c 



ZnS0 4 d 



ZnMet c 



ZnLys c 



SEM b 



Bone 



1.0 



.9 



.9 



1.2 



1.1 



.3 



Bone Marrow 



9 



10 



11 



10 



6 



7 



Hoof 



3.2 



3.3 



3.5 



3.5 



2.4 



1.9 



Kidney 



41 



41 



66 



43 



53 



31 



Liver 



1076 



1299 



1365 



1239 



1201 



381 



Muscle 



10 £ 



7 g 



6 g 



5 g 



6 g 



2.3 



Pancreas 



13 



9 



10 



5 



9 



4 



a DMB= Dry matter basis, bone also fat free basis. 



b n=6. c n=8. d n=7 . 



e SEM = Standard Error of the Mean. 



f,g Means with different subscripts across row differ (P < .05) 



Most tissue Cu concentrations did not differ (P > .05) 

 among treatments and remained relatively constant. Mean 

 muscle Cu concentration (10 mg/kg), however, was highest (P < 

 .05) for the control group. There was a large Cu accumulation 

 in the livers of these animals and was probably due to the 

 high dietary Cu (70 mg/kg) levels. 



Discussion 



Unlike in chapter 3, where Zn intake was a minimum of 75 

 mg/d, Zn levels for the basal diet (16 to 20 mg/kg) for this 

 trial with sheep were well below the marginal level of 30 

 mg/kg (NRC, 1985) . Furthermore, since the animals were only 

 given 1 kg of feed, their actual Zn intake from the basal diet 

 was only 16 to 20 mg/d. 



