Improvement in lamb performance on barley based diet supplemented with zinc

An experiment of 70 days was conducted on 20 male lambs (6-7 months of age) to determine the effects of Zn supplementation (ZnSo4 and Zn-proteinate) in a barley based diet on mineral profile, some serum and plasma metabolites and performance in lambs. Animals were randomly allotted to 4 treatments including;1) basal diet containing 22.47 mg Zn/kg DM, without supplementary Zn (control); 2) basal diet + 40 mg Zn/kg DM as ZnSO4 (ZnSO4 40); 3) basal diet + 20 mg Zn/kg DM as Zn-proteinate (Zn-Pro 20), and 4) basal diet + 40 mg Zn/kg DM as Zn-proteinate (Zn-Pro 40). The basal diet was provided according to NRC (2007) to meet or exceed lambs requirements except Zn. Blood samples were taken on days 28, 30, 65 and 70 before morning feeding. Daily feed intake, plasma Ca and Cu and beta-carotene concentration did not differ significantly between treatments. Plasma Zn concentration, serum vitamin A concentration, alkaline phosphatase (ALP) and superoxide dismutase (SOD) activity differed significantly between control and Zn supplemented groups (P < 0.05) as Zn supplementation improved these parameters. Average daily gain and feed efficiency improved with Zn supplementation (P < 0.05). The results of this study show that Zn improved performance of lambs and adding 20 mg Zn/kg DM to the basal diet might be sufficient to meet the Zn requirement of the lambs.