Selenium nanoparticles (Se-NPs), a nanoscale form of selenium, and sodium selenite (SS), an inorganic selenium compound, were incorporated into poultry feed to assess their effects on bioaccumulation, DNA damage, and cellular health. This study compared the effects of Se-NPs and SS on selenium bioaccumulation in blood, feathers, and eggs, along with their potential impact on DNA damage in quails. A total of 480 quails (14-day-old) were distributed into 5 groups. Each group consisted of 96 birds, arranged into 6 replicates (16 quails per replicate) with sex ratio 1 male: 3 females, 1st group as control, fed by basal diet
2nd and 3rd group were supplemented with Se-NPs (0.2 mg/kg and 0.4 mg/kg), 4th and 5th groups were fed with SS (0.2 mg/kg and 0.4 mg/kg), respectively. The results showed that highest bioaccumulation occurred in blood, feathers, eggshells, and egg content in quails fed with higher doseage of Se-NPs. Maximum selenium bioaccumulation was found in eggshells due to their porous structure. Quails treated with Se-NPs (0.4 mg/kg) and SS (0.2 mg/kg and 0.4 mg/kg) exhibited DNA damage, with more pronounced adverse effects observed in groups receiving SS. The correlation between groups and DNA damage was noted, there is positive correlation between Length of Head (LHead), Length of Tail (LTail) and Length of Comet (LComet) parameters related to different groups of quails. The study indicated that while Se-NPs led to the highest bioaccumulation, they were less harmful in terms of DNA damage compared to SS.