Morphology and histology of the developing ovary in Malaysian village chicken (Gallus gallus domesticus) chicks

The Malaysian village chicken (MVC; Gallus gallus domesticus) is an indigenous breed derived from the red junglefowl (Gallus gallus), exhibiting slower growth and reproductive rates. The MVC plays an important ecological role in local farming systems and represents a valuable genetic resource. However, detailed information on ovarian development in this breed remains limited. This study provides the first comprehensive morphological and histological characterization of the developing ovary in MVC chicks. A total of 20 chicks aged 1, 2, 4, and 8 weeks (n = 5 per age group) were examined. These MVC chicks possessed a single functional left ovary positioned ventromedially to the cranial lobe of the left kidney. Age-related gross morphological changes were evident in size, shape, color, and consistency. Histologically, significant (p < 0.05) increases in cortical and medullary thickness were observed, with follicular growth progressing from primordial to primary and more advanced stages from 2 weeks after hatching, with cortical lobulation becoming prominent by 8 weeks. The proportion of primordial follicles (approximately 88%–89%) remained high across 2–8 weeks, indicating the maintenance of the ovarian reserve. These findings provide novel insight into MVC reproductive biology and establish baseline data to guide future studies on avian reproduction, development, and conservation in indigenous chicken populations.