PRINCIPAL COMPONENT ANALYSIS OF PHENOTYPIC TRAITS TO EVALUATE GENETIC DIVERSITY AMONG THREE INDIGENOUS NIGERIAN GOAT BREEDS

This study investigated the genetic diversity of three indigenous goat breeds in Nigeria West African Dwarf (WAD), Red Sokoto, and Sahel goats using Principal Component Analysis (PCA) based on phenotypic traits to identify those with the highest discriminative power. A total of 90 goats were randomly selected, comprising 30 individuals from each breed under the same environmental conditions. Nine morphometric traits were measured: body weight, body length, height at withers, rump length, rump width, front leg length, hind leg length, cannon circumference, and chest (heart) girth. PCA was applied to reduce data dimensionality and identify patterns of trait variation across breeds. The communalities of the traits ranged from 0.687 to 0.939, indicating a high proportion of trait variance explained by the extracted components. Notably, cannon circumference (0.939), front leg length (0.876), and heart girth (0.875) exhibited the highest extraction values. Three principal components with eigenvalues greater than one were retained, accounting for a cumulative variance of 83.60%, thereby confirming the robustness and adequacy of the dataset for morphometric differentiation. The first component (PC1), which explained 52.27% of the total variance, was primarily associated with overall size and body conformation traits such as height at withers (0.904), hind leg length (0.897), and heart girth (0.830). PC2 (18.47%) was dominated by cannon circumference (0.892), while PC3 (12.86%) had rump width (0.759) as the highest loading variable. PCA provided a practical tool for informed decision-making in selection, conservation, and breeding, highlighting traits with strong breed-specific discriminative potential.