Three hundred sixty healthy Ross x Ross 1-day-old broilers were used to study the effects of zinc glycine chelate (Zn-Gly) on growth performance, hematological, and immunological characteristics. All broilers were randomly assigned into six treatments. Diets were as follows: (1) control (containing 29.3 mg Zn kg(-1) basic diet [0-3 weeks] and 27.8 mg Zn kg(-1) [4-6 weeks]); (2) basic diet plus 30 mg Zn kg(-1) from Zn-Gly; (3) basic diet plus 60 mg Zn kg(-1) from Zn-Gly; (4) basic diet plus 90 mg Zn kg(-1) from Zn-Gly; (5) basic diet plus 120 mg Zn kg(-1) from Zn-Gly; (6) positive control, basic diet plus 120 mg Zn kg(-1) from zinc sulfate (ZnSO(4)). After the 21- and 42-day feeding trials, the results showed that both of Zn-Gly and ZnSO(4) could improve the growth performance of broilers, with the greatest average daily feed intake observed in the broilers fed 90 mg Zn kg(-1) from Zn-Gly, but the greatest average daily gain observed with 120 mg Zn kg(-1) from Zn-Gly (0-3 weeks) and 90 mg Zn kg(-1) from Zn-Gly (4-6 weeks). Adding additional Zn-Gly improved the levels of immunoglobulins (IgA, IgM, and IgG) and the contents of total protein and Ca in serum and increased the immune organs index especially with 90 mg Zn kg(-1) as Zn-Gly. However, there were no significant differences in responses to complements (C3 and C4) and albumin in serum among the treatments.

One hundred twenty crossbred piglets (Duroc x Landrace x Yorkshire) were used to determine the effects of dietary zinc glycine chelate on growth performance, tissue mineral concentrations, and serum enzyme activity. All pigs were allotted to four treatments and fed with basal diets supplemented with 0, 50, and 100 mg/kg Zn as zinc glycine chelate or 3,000 mg/kg Zn as zinc oxide (ZnO). After the 35-day feeding trial, results of the study showed that, compared to the control, average daily gain was improved (P < 0.05) for pigs fed 100 mg/kg Zn from zinc glycine chelate or 3,000 mg/kg Zn from ZnO and Zn concentrations in serum and M. longissimus dorsi were significantly enhanced by 100 mg/kg dietary zinc glycine chelate and 3,000 mg/kg ZnO. In addition, supplementation of 100 mg/kg zinc glycine chelate decreased (P < 0.05) the liver Fe level, liver Zn level, spleen Cu level, and kidney Cu level compared to that of the 3,000-mg/kg ZnO group. For feces mineral excretion, 3,000 mg/kg Zn from ZnO greatly increased the concentration of fecal Zn (P < 0.01) and Mn (P < 0.05) compared to that of the control or the 100-mg/kg zinc glycine chelate group. Moreover, alkaline phosphatase and Cu/Zn superoxide dismutase activities of pigs in 100 mg/kg zinc glycine chelate and ZnO treatments were greatly higher than that of the control. The results of present study showed that supplementation with zinc glycine chelate could improve growth and serum enzyme activities and could also decrease zinc excretion in feces in weanling pig compared to high dietary ZnO.

160 crossbred (Duroc x Landrace x Yorkshire) gilts averaged 21.25 kg body weight were used to study the effects of dietary copper (II) sulfate (CuSO4) and copper proteinate (Cu-Pr) on growth performance, plasma Cu concentration, ceruloplasmin activity, and erythrocyte Cu/Zn-superoxide dismutase (SOD) activity. All pigs were allotted to four treatments and fed with basal diets supplemented with 0 (control), 250 mg /kg Cu as CuSO4, and 50 and 100 mg/kg Cu as Cu-Pr. Growth performance was determined based on two growth phase (phase 1: days 0 to 15, phase 2: days 15 to 30). After 30 days of the treatment, 16 pig blood samples (four per treatment) were collected for indexes of copper status determination. The experimental results showed that compared with control, pigs fed with 250 mg Cu/kg as CuSO4 and 100 mg Cu/kg as Cu-Pr had higher average daily gain and average daily feed intake in the whole growth phase (d 0 to 30). In addition, 250 mg Cu/kg as CuSO4 and 100 mg/kg Cu as Cu-Pr enhanced plasma ceruloplasmin activity (P < 0.05), and 100 mg/kg Cu as Cu-Pr increased erythrocyte Cu/Zn-SOD activity (P < 0.01) compared with the control. There was no obvious treatment response on plasma Cu concentration in the present study.