Abstract: An experiment designed to have 9 Cu treatments[3 Cu levels,10,150 and 250 mg·kg^-1 and 3 Cu forms,Cu-AA(amino acid copper),CuSO₄(copper sulfate) and TBCC(tribasic copper chloride)]was carried out on effect of addition of Cu in basic dietary on Cu digestibility of 27 crossbred growing pigs(LandraceLargewhiteDuroc) about 30 kg in body weight and Cu availability in their dungs.Results show that the effect of Cu source on Cu digestibility of pigs did not vary much(P>0.05),but the effect of Cu level did.It was more significantly when the Cu level was high(P<0.05).Availability of Cu in the pig dung varied sharply with the Cu forms.It was higher when CuSO₄ was added than when Cu-AA or TBCC was added(P<0.05),but it was more or less the same for the latter two(P>0.05).In terms of potential available Cu in pig dung,the two treatments of Cu-AA and CuSO₄ were quite similar(P>0.05) but higher than the treatment of TBCC(P<0.05).Naturally,unavailable Cu in the pig dung from Treatments TBCC was significantly higher than those from Treatments Cu-AA and CuSO₄(P<0.05).Regardless of forms of Cu added,the content of Cu in the pig dung from pigs fed with a higher level of copper in the dietary was higher than those fed with a lower level of copper in the dietary(P<0.05).

Key words: Cu, copper digestibility, speciation of copper in manure, pig