Morphological Characterization of Merino Sheep in Different Agro-Ecological Zones of Lesotho

The Lesotho Merino sheep is a native Merino strain formed from the indigenous fat-tailed sheep through crossbreeding over many generations. This study is aimed at phenotypically characterizing Merino sheep locally bred in four agro-ecological zones of Lesotho, facilitating easy selection based on morphological traits. Body weight (BW), body length (BL), withers height (WH), rump height (RH), chest girth (CG), rump length (RL) and rump width (RW) were measured in 2515 mature shorn Merino ewes from four agro-ecological zones: mountains (n = 1554), the Senqu River Valley (n = 350), lowlands (n = 395) and foothills (n = 216). A multivariate discriminant analysis procedure identified and quantified the traits that differentiate the Merino sheep across these agro-ecological zones. The structure matrix indicated that RL had the highest loading (0.82) in Function 1, whereas WH (0.6) and head width (0.36) exhibited the highest loadings in Functions 2 and 3, respectively. The standardized canonical discriminant coefficients showed that RL (1.02) and RW (0.60) were the highest in Function 1, whereas CG (0.65) and RH (0.41) were in Function 2, and WH (1.61) and RW (0.41) were in Function 3. The Mahalanobis distance was highest between the lowlands and the Senqu River Valley (3.46) and lowest between the mountains and foothills (0.61). Principal component analysis (PCA) extracted three components per agro-ecological zone. Morphological traits differentiate Merino sheep across the agro-ecological zones, suggesting the presence of two strains: one suited for the mountains, the Senqu River Valley, and foothills and another suited for the lowlands.