It was valuated the hypothesis that, like the neutrophils of mammals, the superoxide production by avian heterophils is associated with functional maturity of these cells. Were used twenty ostriches of both sexes, divided into two groups: 1-|30 days (n=10) and 180-|240 days (n=10) of age. The oxidative metabolism by heterophils was estimated by superoxide production in not stimulated cytochemic test of nitroblue terazolium (NBT). The average percentage of heterophilic NBT reduction in ostriches with up to 30 days of age (0.7±1,3) was lower (P<0,001) than that observed in those aged between six and eight months (6,2±2,7). It was concluded that the oxidative metabolism by ostriches' heterophils increases with age, suggesting that lower superoxide production reduces the ability bactericide and may contribute to high mortality in the first three moths of life.
unspecific immunity; polymorphonuclear; superoxide; nbt; ratite
