Principal Component Analysis of the Female Pengging Soloan Duck Based on Morphometric Traits

Abstract

The Pengging Soloan duck is an emerging indigenous genetic resource from Central Java, Indonesia, recognized for its adaptability and egg-laying potential. However, its phenotypic characterization remains limited compared with established Indonesian duck breeds such as Mojosari, Tegal, and Magelang ducks. This study aimed to characterize 70 adult female Pengging Soloan ducks aged 5 6.5 months using Principal Component Analysis (PCA) based on 13 morphometric traits. Descriptive statistics, Pearson’s correlation, and PCA with Varimax rotation were applied. Most morphometric traits showed low variability (CV<10%), indicating a relatively homogeneous population, although moderate variation was observed in neck length (10.74%), pubic width (12.26%), and shank length (10.20%). Significant positive correlations were identified among cranial traits, particularly between Beak Length (BeL) and Beak Width (BeW) (r = 0.563). PCA extracted six principal components explaining 72.10% of the total variance, with the first component primarily associated with cranial morphology, while subsequent components reflected body conformation, limb dimensions, and pelvic traits. The separation between cranial and post-cranial components suggests distinct patterns of morphological organization and developmental modularity. In addition, the pubic width emerged as an important contributor to phenotypic variation, although its relationship with reproductive performance was not directly evaluated. The findings provide preliminary baseline information on the morphometric structure of Pengging Soloan ducks. However, the results should be interpreted cautiously due to the relatively small sample size (n = 70), single-location sampling, exclusion of male individuals, and the absence of productivity data. Future studies involving large populations, multiple locations, both sexes, and the integration of production and molecular data are required to achieve more comprehensive breed characterization.