Association between genomic indices and growth performance in Charolais calves under commercial production conditions

Abstract

Growth performance is a key determinant of productivity and economic efficiency in beef cattle production. This study aimed to evaluate the relationships between genomic indices and growth traits in Charolais calves under practical production conditions, as well as to assess the influence of calf sex and season of birth. A total of 62 Charolais calves were included in the study. Growth performance was evaluated using birth weight and average daily gain (ADG) across three periods (0–210, 211–365, and 0–365 days). Genomic evaluation was based on GD Scan–derived indices, including ease of birth (Nai g), growth capacity (Cr g), muscular development (DM g), skeletal development (DS g), calving ability (Vel g), and maternal milk index (Lai g). Statistical analyses included general linear models, Pearson correlation, and simple linear regression. Male calves exhibited higher birth weight and ADG compared with females across all growth periods, whereas the effect of season was limited. Strong positive correlations were observed between growth-related genomic indices and calf performance, particularly for Cr g (r = 0.749 for ADG 0–365; p < 0.001). Regression analysis confirmed that Cr g had the strongest predictive value for growth (β = 0.143; R² = 0.561; p < 0.001), followed by DM g and Lai g. In contrast, calving ease (Nai g) showed a significant negative association with growth traits. The results suggest that genomic indices, particularly those related to growth and maternal effects, can be used as predictors of growth performance in Charolais calves. These findings support the integration of genomic tools into beef cattle breeding programs to improve selection accuracy and production efficiency.