Relative Bioavailability of Different Zinc Sources Based on Tissue Zinc Concentration in Broiler Chickens

This research project was conducted to evaluate bioavailability and chemical properties of different zinc sources in broiler chickens when fed by practical diets. For that, 312 day-old male Ross 308 broiler chicks were fed from 8-28 day to estimate the biological availability of four zinc sources. Chicks were allocated randomly to 13 experimental diets in a 3 × 4 factorial design. Diets included an unsupplemented corn-soybean meal basal diet, or the basal diet supplemented with 100, 150 or 200 mg/kg of DM as either zinc sources. Supplementation of basal diets by different zinc levels and sources had no effects on feed intake and body weight gain of chicks during the first and the second weeks of experimental periods, but feed conversion ratio in the first and the second week, feed intake, body weight gain, feed conversion ratio in the third week and the total experimental periods were significant (P < 0.05) affected by supplementary levels of zinc sources. Tibia and liver zinc content was increased linearly by adding different levels of zinc sources except zinc oxide A in the basal diet (P < 0.05). The highest zinc concentration in the pancreas was observed only in the basal diet supplemented with 200 mg zinc oxide B per kg of diet in compare to basal diet (P < 0.05). Using the slope ratio methods from the regression of zinc concentration in the tibia, liver and pancreas on zinc intake from different supplementary zinc levels showed that the highest relative bioavail-ability value based on tibia bone zinc concentration was estimated when used 150 mg different zinc sources in kg of basal diet, but relative bioavailability value was also estimated based on pancreas zinc content showing a linear increase by increasing different level of zinc sources. In conclusion Bioplex Zn in the same level was more bioavailabe than others.