Comprehensive Assessment of Silver Bioaccumulation and DNA Damage Effects in Coturnix coturnix japonica via Blood, Feather, and Egg Using Two Different Sources

This study examined the effects of Ag-NPs and AgNO₃ on silver accumulation in the blood, feathers, eggshells, and egg contents of Japanese quails, as well as their potential to cause DNA damage. A total of 480 (fourteen-day-old) quails were divided into five groups of 96 birds each, arranged into six replicates of sixteen birds with a sex ratio of four males to twelve females. Birds were housed in cages measuring 120 × 60 × 50 cm, and the trial lasted for 65 days. At the end of the trial, six birds per replicate (36 birds per group) were randomly selected and slaughtered for sample collection. Blood was collected via wing vein puncture, feathers were plucked from the breast region, and eggs were collected daily for analysis of eggshell and internal contents. The first group served as a control and was fed a basal diet, while the second and third groups received Ag-NPs at doses of 10 mg/kg and 20 mg/kg, respectively. The fourth and fifth groups were given AgNO₃ at the same concentrations. The results showed that the highest silver accumulation occurred in all tissues in quails fed the higher dose of Ag-NPs. The greatest accumulation was observed in the eggshells, likely due to their porous structure, which facilitates metal deposition. Both Ag-NPs (20 mg/kg) and AgNO₃ (10 and 20 mg/kg) induced DNA damage, although the damage was more severe in the groups exposed to Ag-NO₃. A positive correlation was observed between treatment groups and comet assay parameters, indicating increased DNA fragmentation in exposed birds. In conclusion, the study demonstrated that although Ag-NPs resulted in higher silver accumulation, they caused less DNA damage compared to silver nitrate. These findings highlight that nanoparticulate silver may present a less genotoxic alternative to ionic silver forms for use in poultry systems. Future studies should focus on long-term exposure effects, molecular pathways of oxidative stress and DNA repair, and the safe threshold levels of Ag-NPs to optimize their use in animal nutrition.