Effects of different stock density and male animal presence on growth, reproductive characteristics and some blood parameters in male and female japanese quails (coturnix coturnix Japonica)

This study was conducted to investigate the growth performance, reproductive traits, and selected blood parameters of Japanese quails (Coturnix coturnix japonica) housed under different stocking densities (80, 120, and 160 cm²/quail) and categorized based on the presence or absence of male individuals (male (+): Group A; male (−): Group B). According to the data obtained, the highest average daily feed intake per bird, calculated weekly, was recorded in Group 160 A during weeks 2, 3, and 4 following the acclimation period, with values of 11.76 g, 18.81 g, and 21.79 g, respectively. The highest daily live weight gain was observed in Group 160 B during week 5 (8.88 g), in Group 160 A Female during week 6 (6.45 g), in Group 80 A Female during week 7 (3.02 g), in Group 160 A Female during week 8 (4.03 g), and in Group 80 A Male during weeks 9 and 10 (2.19 g and 1.42 g, respectively). Feed conversion ratio (FCR) was higher in groups with greater stocking density during the initial weeks (e.g., 1.89 in Group 80 A), and lower in groups with lower stocking density (e.g., 2.16 in Group 160 B). However, by week 4, this trend reversed, with FCR values of 3.07 in Group 160 B and 3.36 in Group 80 A. The overall mean of the largest follicle diameter was 16.33±3.00 mm, with the highest value measured in Group 80 B (18.86±1.20 mm). Four days after the onset of first egg laying, the highest egg production rate during the laying period was observed in Group 160 B (81.47%), followed by Group 120 B (80.66%) and Group 120 A (76.19%). Regarding egg quality, the highest average egg weight was recorded in Group 120 B (12.31±0.93 g), while the lowest was in Group 80 B (11.45±0.55 g). The overall mean egg weight was 11.86±0.97 g. Differences in egg weight were found to be statistically insignificant. Haugh unit was negatively correlated with egg weight (r = −0.045) and shell weight (r = −0.034), whereas a strong positive correlation was found with shell thickness (r = 0.276; p < 0.05). Significant differences were observed among groups in terms of WBC (10³/µL) values (p < 0.001). The highest WBC value was measured in Group 80 A (97.68±13.39 ×10³/µL), and the lowest in Group 160 B (56.03±10.17 ×10³/µL). Regarding liver weights, Group 120 B had the highest mean value (9.19±3.13 g), which was statistically significant (p < 0.05). Sex-based differences in liver weight were also identified, with females exhibiting higher liver weights (7.64±1.89 g) compared to males (4.13±1.32 g), and this difference was statistically significant (p < 0.001)