DOCILIDADE E SELEÇÃO FENOTÍPICA DE NOVILHAS DE CORTE SUPLEMENTADAS A PASTO NO PERÍODO CHUVOSO EM COMBINADO - TO

Abstract

This study aimed to evaluate the phenotypic characteristics and behavioral traits of beef heifers subjected to different types of pasture supplementation during the rainy season in Combinado, Tocantins, Brazil. A total of 54 heifers, approximately 14 months old, were allocated into three experimental groups: Lot A received mineral supplementation with additives (Mineral UP); Lot B was fed a protein-energy supplement (Total Diet); and Lot C received a protein supplement (Blond 200). The evaluations included visual assessments of body conformation, docility, body condition score (BCS), and udder development (teteia) as a reproductive selection criterion. Data collection was conducted through standardized photographs and linear measurements over a 45-day period, across three distinct time points. The results revealed visible improvements in phenotypic parameters, particularly in Lot B, where heifers showed enhanced rump conformation, muscle deposition, and increased docility—traits highly desirable for reproductive females. The protein-energy supplementation stood out by providing a better nutritional balance, evidenced by improved coat brightness and herd uniformity. Furthermore, the docility observed in some heifers was considered a favorable trait for reproductive and welfare management. It is concluded that the strategic use of appropriate supplementation, combined with precise phenotypic evaluation, is an effective approach for selecting heifers with high zootechnical and reproductive potential in beef production systems.