An experiment was conducted with 312 day-old male broiler chicks in grower phase (8-28d) to estimate the biological availability of four sources of zinc (Zn); zinc sulfate (ZnSO 4 ･H 2 O), two sources of zinc oxide (ZnO FG1 and ZnO FG2) and Bioplex Zn. Zinc sulfate was used as the standard in the bioavailability assay. Chicks were allotted randomly to 13 dietary treatments with 6 birds per replicate and 4 replicates per treatment, that included an unsupplemented corn-soybean meal basal diet (25.50 mg of Zn/kg of DM), or the basal diet supplemented with 100, 150 or 200 mg/kg of DM as either ZnSO 4 ･H 2 O (33% Zn), zinc oxide FG1 (72% Zn), zinc oxide FG2 (75% Zn) or Bioplex Zn (15% Zn). Dietary zinc level and source had no effect (P＞0.05) on feed intake or body weight gain of chicks during first and second weeks of experimental periods, but feed conversion ratio in the first and second week and feed intake, body weight gain or feed conversion ratio in third week and total experimental periods were significant difference between treatments (P＜0.05). Using the slope ratio methods from the regression of weight gain on supplemental zinc intake. The relative biological availability values using body weight gain were estimated to be 59, 99 or 45 for three levels of zinc oxide FG1, 64, 78 or 31 for three levels of zinc oxide FG2 and 151, 200 or 147 for three levels of Bioplex Zn, respectively. From the standpoint of bioavailability, Bioplex Zn was more available to broiler chicks than zinc from other sources and can be used by the feed industry as sources of supplemental zinc for broiler chickens.

An experiment was conducted with 312 day-old male broiler chicks in grower phase(8-28d) to estimate the biological availability of four sources Zinc (Zn), Zinc sulfate(ZnSO 4. H 2 O), two sources of Zinc oxide(ZnO FG1 and ZnO FG2) and Bioplex Zn. Zinc sulfate (ZnSO 4. H 2 O) was used as the standard in the bioavailability assay. Chicks were allotted randomly to 13 dietary treatments with 6 birds per replicate and 4 replicates per treatment, that included an unsupplemented corn-soybean meal basal diet (25.50 mg of Zn/kg of DM), or the basal diet supplemented with 100, 150 or 200 mg/kg of DM as either ZnSO 4. H 2 O (33 % Zn), Zinc oxide FG1(72%Zn), Zinc oxide FG2 (75%Zn) or Bioplex Zn (15% Zn). Dietary Zn level and source had no effect (P>0.05) of feed intake or body weight gain of chicks during first and second weeks of experimental periods, but feed conversion ratio in the first and second week and feed intake, body weight gain or feed conversion ratio in third week and total experimental periods were significant difference between treatments (P<0.05). The relative biological availability values using body weight gain were estimated to be 59, 99 or 45 for three levels of Zinc oxide FG1, 64, 78 or 31 for three levels of Zinc oxide FG2 and 151, 200 or 147 for three levels of Bioplex Zn, respectively. From the standpoint of bioavailability, Bioplex Zn was more available to broiler chicks than Zn from other sources and can be used by the feed industry as sources of supplemental Zn for broiler chickens.