Black nightshade (Solanum nigrum L.) is known to contain bioactive compounds with antioxidant properties. This study aimed to evaluate the effects of black nightshade fruit extract as a phytobiotic on the performance and egg quality of laying quails (Coturnix-coturnix japonica). A total of 160 female quails, aged six weeks, were randomly assigned to four treatment groups with four replications, each containing ten birds. The treatments included a control group (P0) and three experimental groups receiving drinking water supplemented with 2 mL/L (P1), 4 mL/L (P2), and 6 mL/L (P3) of black nightshade extract. The parameters observed included feed intake,quail day production, egg production, egg weight, feed conversion ratio (FCR), physical egg quality (egg index, percentage of albumen, yolk and eggshell weight, eggshell thickness, yolk color score, haugh unit, albumen and yolk index) and malondialdehyde (MDA) levels in egg yolk. The cold-press extraction method offers advantages in terms of cost-effectiveness and environmental sustainability. This technique avoids the use of solvents and heat, which helps preserve thermosensitive compounds. However, a notable limitation is that the extracted compounds remain in their complex, non-degraded forms, which may limit the efficiency of isolating certain bioactive constituents—especially those such as phenolics, flavonoids, and alkaloids that typically require solvents for effective extraction. Phytochemical screening conducted in this study revealed low concentrations of several compounds, and notably the extract of Solanum nigrum fruit obtained using a cold-press juicer method showed no presence of triterpenoids or steroids. The results showed that black nightshade extract supplementation did not significantly affect quail performance (p>0,05). However, significant improvements (p<0,05) were observed in physical egg quality parameters, particularly in albumen index, yolk color, and haugh unit at higher doses (P2 and P3). The MDA content in the yolk significantly decreased with increased extract concentration. |