Effect of copper, ferrous iron and zinc from different sources on growth performance and fecal copper, ferrous iron and zinc balance in growing pigs

The objective of the present study was to evaluate the effect of dietary supplemented with copper, ferrous iron and zinc together from their proteinates or sulphates on growth performance, plasma concentration and balance of copper, ferrous iron and zinc in pigs at different growth stages. Three growth experiments and one mineral balance test were included in present study. In comparison with diet supplemented with copper, ferrous iron and zinc from sulfates together, diet supplemented with lower concentrations of copper, ferrous iron and zinc together from their proteinates significantly increased (P < 0.05) the feed efficiency in all three growth experiments and also increased (P < 0.05) the average daily gain (ADO) in Exp. 1, however, no difference of average daily feed intake (ADFI) in Exp.1 and ADG, ADFI and plasma concentrations of copper, ferrous iron and zinc were observed in Exp. 2 and 3, respectively. In mineral balance trail, pigs consumed copper, ferrous iron and zinc from their proteinates decreased copper, ferrous iron and zinc excretion by 91% (P < 0.01), 45% (P < 0.01) and 71% (P < 0.01) compared with pigs that consumed these minerals from sulfates, respectively. We concluded that dietary supplemented with copper, ferrous iron and zinc from their proteinate sources at the levels of 20, 100 and 40 mg/kg together have a growth-promoting effect on pigs at early growth stage and decrease copper, ferrous and zinc elimination into the environment.