The effects of Viburnum opulus L. fruit powder on the performance, egg traits, and egg cholesterol of laying Japanese quails.

This study was conducted to evaluate the potential use of Viburnum opulus L. (VO) fruit as a phytogenic feed additive in the diets of Japanese quails (Coturnix coturnix japonica) and its effects on egg quality parameters and egg yolk cholesterol concentration. A total of 176 Japanese quails aged 30 weeks were used in the study. They were allocated into 4 main groups with 11 replicates, each consisting of 3 females and 1 male. The experimental groups consisted of the control (VOFP0) and the VOFP5, VOFP10, and VOFP15 groups, which received the basal diet supplemented with Viburnum opulus L. fruit powder (VOFP) at 0, 5, 10, and 15 g kg-1, respectively. The experiment lasted for 8 weeks. According to the results, dietary VOFP supplementation had no statistically significant effects on the quails' body weight, body weight gain, and feed conversion ratio (FCR) ( P > 0.05 ). The absence of adverse effects on growth performance parameters suggests that VOFP was well tolerated under the conditions of this study. The lowest total feed consumption was recorded in the VOFP15 group, whereas the addition of VOFP5 resulted in the highest total egg weight (1828.60 g). Evaluation of egg quality parameters showed that VOFP supplementation improved selected internal egg quality parameters. The dose of VOFP5 significantly increased egg yolk height and yolk index compared with the control group ( P < 0.01 ). Regarding shell characteristics, VOFP supplementation reduced shell weight, whereas no adverse changes were observed in shell thickness and breaking resistance. Egg yolk cholesterol concentration showed VOFP supplementation numerical reductions at several sampling points; however, a statistically significant decrease was observed only in the sixth week in the VOFP15 group compared with the control group ( P < 0.05 ). In conclusion, the inclusion of VOFP5 in quail diets improved selected egg internal quality parameters, while VOFP15 showed a potential cholesterol-modulating effect, with a significant reduction observed only in the sixth week of the experiment. Considering the limited information available on VOFP supplementation in poultry nutrition, these findings provide preliminary evidence regarding the potential use of VOFP as a phytogenic feed additive and support further investigations into its effects on egg quality characteristics and potential functional properties of eggs.