تخمین زیست فراهمی منابع مختلف عنصر روی در جوجه های گوشتی تغذیه شده با جیره های نیمه خالص

     An experiment was conducted to estimate the bioavailability and evaluation chemical properties of different zinc sources such as zinc sulfate, zinc oxide A, zinc oxide B and Bioplex Zn in broiler chickens fed by semi-puirfeid diets., At first, for chemical and solubility evaluation of different zinc sources in different solvents based on standards methods, 3 samples each containing 1 and 0.1 g, respectively, were used the results showed that zinc concentration is varied from 15 % in Bioplex Zn to 75 % in zinc oxide A. The highest solubility about 100 % obtained in the double distilled water, 0.4% HCL and 2 % citric acid is related to zinc sulfate but the lowest solubility observed in the double distilled water, 0.4% hydrochloric acid and 2 % citric acid is related to Bioplex Zn. In the following, for study the bioavailability of different zinc sources, of a 13 semi-purified diets supplemented by 50,100 or 150 mg of different zinc sources per kg of diet in feeding of 260 Ross-308 male broiler chickens in completely randomized design with 4 replicates and 6 birds per each in cage system from 8-21days of age were used. For estimation of relative bioavailability slope ratio method was used. In this method relative bioavailability of different zinc sources, calculated by dividing of regression equation coefficient to regression equation coefficient of zinc sulfate as a standard sources. The highest bioavailability value, based on weight gain, was obtained in diets supplemented by 100 mg zinc oxide A and B, but the highest bioavailability value for Bioplex Zn was found in 50 mg zinc supplemented per kg of basal diet (P<0.05). The highest amount of zinc bioavailability based on tibia zinc concentration was obtained in 50 mg zinc supplemented per kg of diet with zinc oxide A, but according to the zinc concentration in liver and pancreas, the highest value were seen in basal diet supplemented whit 100 mg Bioplex Zn per kg of diets (P<0.05).