Abstract
Sex-specific histological changes during post-hatching skeletal maturation remain poorly understood in domestic geese. The study aimed to investigate the microstructural characteristics of femoral bone associated with sexual size dimorphism in domestic goose (Anser anser), where males typically exhibit greater body mass than females. To achieve this, femoral bone samples were collected from 18 domestic geese (9 males, 9 females) at 1, 6, and 24 weeks post-hatching (n = 3 per sex per age group). After standard histology using hematoxylin and eosin alongside Masson trichrome stains, we determined three parameters: Active Cartilaginous Zone Thickness (ACZT), Cortical Bone Thickness (CBT), and Total Bone Diameter (TBD). Data were statistically analyzed using an independent samples t-test to compare between sexes. At 1-week post-hatching, males showed significantly higher values for both ACZT (1499.34 ± 66.2 vs. 1346.84 ± 32.4 µm, P = 0.023) and CBT (429.92 ± 4.76 vs. 413.74 ± 6.79 µm, P = 0.023). By 6 weeks, the ACZT difference had disappeared (P = 0.745), whereas CBT remained significantly higher in males (1093.35 ± 18.5 vs. 939.26 ± 69.7 µm, P = 0.020). At 24 weeks (adulthood), males exceeded females in all three parameters: CBT (1383.88 ± 10.4 vs. 1281.28 ± 14.7 µm, P = 0.001), ACZT (210.58 ± 5.22 vs. 172.77 ± 4.09 µm, P = 0.001), and TBD (8199.13 ± 114.1 vs. 7739.90 ± 133.6 µm, P = 0.011). The histological analysis confirmed that male cortices were significantly thicker, with a slightly thicker growth plate remnant, than those of females. In this way, the phenomenon of sexual dimorphism in goose femoral histology appears at the age of one week after hatching and is accentuated with age. This finding suggest sex-specific trajectories in appositional baseline histological data for future studies of avian development.