Morteza Mokhtari

This study aimed to quantify a latent variable for body size (BS) in cattle by using six morphometric traits, including body height at withers (HW), body length (BL), hip width (HpW), chest depth (CD), shoulder width (SW), and chest width (CW). The statistical measures for goodness of fit, including comparative fit index (CFI), Tucker-Lewis Index (TLI), and standardized root mean square residual (SRMR), were 0.94, 0.91, and 0.05, respectively, and appropriately indicate the adequacy of the confirmatory factor model proposed for the latent variable of BS. The standardized factor loadings of HW, BL, HpW, CD, SW, and CW for describing BS were 0.83, 0.76, 0.82, 0.89, 0.80, and 0.40, respectively, and statistically significant (P<0.01), implying that the observed variables were appropriate indicators of the corresponding BS latent trait. All correlations among morphometric traits were positive and statistically significant (P<0.01), ranging from 0.26 (CW-SW) to 0.77 (HW-CD). The correlations between the BS latent trait and the considered morphometric traits were also positive and statistically significant (P<0.01); ranged from 0.42 (CW-BS) to 0.93 (CD-BS). It was concluded that the proposed confirmatory factor analysis model showed adequate fit indices for constructing the BS latent trait, implying that the proposed framework adequately captures the underlying relationships among the observed variables. Overall, the study provided a robust framework for applying BS in contexts such as phenotypic evaluations, where a latent construct can capture the complexity of morphometric traits more effectively than individual traits alone.