Three hundred and eighty four broilers chicks, half males and half females, were used to determine the zinc requirement for broilers in the initial phase (from 8 to 21 days). A basal diet was formulated that meet the nutritional requirements, except for Zn level, which was kept deficient at 12.00 ppm. The treatments consisted of Zn supplementation to the basal diet with Zn oxide, in the levels of 12.0, 37.0, 62.0, 87.0, 112.0 and 137.0 ppm of Zn. The characteristics evaluated were weight gain, feed intake, feed:gain ratio and Zn concentration in the bone, liver and blood serum. There was no effect of Zn levels on performance characteristics and on Zn concentration in liver of birds. There was effect of Zn levels on Zn concentration in serum and bone. Significant interaction between Zn levels and sex was observed only for Zn concentration in bone. The requirement estimations were 86.12 ppm and 85.70 ppm for broilers males and females, respectively, from 8 to 21 days of age. Based on the Zn concentration in the serum, requirement estimated was of 113.55 ppm, however, considering the importance of this mineral in the bone development, requirement of Zn is of 86.12 ppm and 85.70 ppm for male and female broilers from 8 to 21 days of age.
bone; liver; mineral; requirement; serum
