Estimativas de parâmetros genéticos para características reprodutivas, funcional e de carcaça em bovinos da raça Santa Gertrudis.

Abstract

The present study aimed to estimate genetic parameters for age at first calving (AFC), scrotal circumference at yearling (SCY), ribeye area (REA), subcutaneous fat thickness (SFT), marbling score (MAR), and navel score (UMB) in Santa Gertrudis cattle in Brazil. The dataset comprised 4,113 Santa Gertrudis animals, including 1,579 males and 2,534 females, born between 2011 and 2025, from 28 farms and sourced from the Embrapa Geneplus Program database. Data manipulation and preprocessing were performed using R software, and variance and (co)variance components were estimated considering the animal model via REML using BLUPF90 software. The heritability (h²) range for AFC, MAR, and REA was 0.49, 0.37, and 0.28, respectively, indicating significant genetic gains through direct selection. The estimates obtained for SCY (0.07), and UMB (0.05) showed low heritability, which may have been influenced by the number of observations and limited genetic variability in the population. The genetic correlations observed between MAR and SFT (0.53), MAR with SCY (0.43) and REA with SCY (0.62), in addition to the moderate and negative genetic correlation (-0.52) between SCY, indicate favorable genetic gains through indirect selection for these traits.