Multivariate analysis of body morphometric traits in conjunction with performance of reproduction and milk traits in crossbred progeny of Murrah × Jafarabadi buffalo (Bubalus bubalis) in North-Eastern Brazil

摘要

We studied the relationship between body morphometric traits, and their underlying association with milk production (MP), lactation length (LL), first calving interval (FCI) and subsequent calving interval (CI) of crossbred progeny of Murrah × Jafarabadi buffalo aiming to assist in selection programs. We carried out principal component analysis (PCA) of the body morphometric traits, which include breast width (BW), thigh width (THW), hip width (HW), rump width (RW), rump length (RL), body depth (BD), body length (BL), height withers (HEW), rear height (RH), shoulder width (SW), thorax width (TW), loin width (LW), distance from the head to ischium (DHI), and thoracic perimeter (TP). We determined the association of morphometric traits with milk/reproduction traits using canonical correlation analysis (CCA). The analysis revealed that the first six PCA accounted for 82.14% of the total observed variation, and the traits THW, HW, TW, LW, RW, HEW, TP, RH, and BW, accounted for almost half (48.00%) of the total variance indicating a higher contribution in body structural conformation. The first canonical function was significant (p<0.05), accounted for 72.46% of the total variance, and the canonical correlation was 0.56, indicating the dependence between both groups of traits. Higher canonical loadings were obtained for LL (0.49), FCI (0.46), BW (-0.71), BL (-0.56), DHI (-0.34), HEW, (-0.38) and TP (-0.50). These traits were most important for the derivation of canonical statistical variables, and presented a higher canonical correlations (r) between the dependent (LL/FCI) and independent (BW, BL, DHI, HEW and TP) groups. The results could suggest that the body morphometric traits THW, HW, TW, LW, RW, HEW, BD, TP, RH, and BW could play important role in body structural composition, indicating a suitable functional type, and aid designing of selection programs for buffalo breeding.