Effect of various levels of zinc on footpad lesions and some reproductive and blood parameters of broiler breeder

Effect of different levels of zinc supplementation on footpad lesions، reproductive and blood parameters of broiler breeders with 300 hens and 40 roosters of Ross 308 strain with 4 treatments، 5 replicates and 15 hens and 2 roosters in each for 12 weeks was evaluated in a completely randomized design. Dietary treatments were 80، 110، 140 and 170 mg zinc/kg diet. Increasing supplemental zinc level especial 170 mg/kg diet increased hatchability (P<0. 05). Levels of 140 and 170 mg zinc/kg diet significantly improved footpad lesions (P<0/05). In the first phase of incubation، the lowest rate of mortality observed in 140mg zinc/kg diet (P<0. 05). Also، number of large and small size follicles of broiler breeders increased at 170 mg zinc/kg diet (P<0. 05). Blood parameters did not affect significantly. The results of this experiment showed that supplementation of broiler breeders diet with zinc at 140 and 170 mg/kg diet could improve hatchability and had desirable effect on footpad health.