SUMMARY
his study was investigated to determine the effect of zinc source either from organic or inorganic on lambs performance, blood metabolites and carcass characteristics. Fifteen local lambs (about six months old and an average body weight of 26.5± 3.1 kg) were divided into three similar groups (5 lambs each). The control group (G1) was fed the basal diet consisting of wheat straw and concentrates mixture. While, the other two tested groups were fed the same basal diet, supplemented with 20 mg Zn/head/day as Zinc Sulphate (G2) and 20 mg Zn/head/day as Zinc methionine (G3). All animals of these groups were fed 60% of their requirements as concentrate mixture and the rest of other requirements were covered from wheat straw, which was given ad libitum. The experiment was extended for 6 month. The results indicated that the average daily gain (ADG) was higher (P < 0.05) in zinc sulphate and zinc methionine groups than in control group (130 and 132 gm/day vs. 99 gm/day, respectively). There were no significant differences among groups in total feed intake. Feed conversion ratio as dry matter intake/ g gain was improved in zinc methionine and zinc sulphate groups when compared with control one. However, the differences among groups were not significant. Supplementation of Zn-meth increased (P<0.05) the level of zinc in serum as compared with control and zinc sulphate groups. Also, serum cholesterol was higher (p < 0.05) in Zn treated groups than in control one. While, serum concentration of total protein, Albumin, globulin, glucose, triglycerides and total antioxidant capacity (TAC), were not affected by zinc supplementation. Zn supplementation in a form of organic or inorganic had no effect on dressing percentage and carcass cuts in lambs. In conclusion zinc supplementation in form of inorganic or organic may improve lambs performance.