USE OF A MULTIVARIATE SEXUAL DIMORPHISM INDEX: AN EXAMPLE IN Bos taurus L.

Abstract

Sexual dimorphism refers to morphological differences between males and females of the same species, traditionally evaluated using univariate methods (e.g., size) and, less frequently, multivariate approaches that integrate quantitative and qualitative traits. This study proposes the use of the Gower index to assess multivariate sexual dimorphism in Bos taurus L. The robustness of this approach is based on the mean values of the ethnological descriptors from 25 existing taurine cattle breeds (Iberian, European, and Creole). For each breed, nine traits were recorded: two ordinal qualitative traits and seven quantitative continuous traits. The qualitative data considered neck length and dewlap size. The quantitative data considered live weight, height at the withers, longitudinal diameter, dorso-sternal diameter, thoracic perimeter, anterior shank perimeter, and bicostal diameter.  It can be concluded that, by integrating variables of different types, the Gower index is a good indicator of sexual dimorphism in Bos taurus L.