Eficiência hídrica de bovinos Nelore a pasto na fase de recria: interação entre comportamento de consumo de água, microclima e composição de carcaça

Abstract

Abstract BERWERTH, L. M. Water efficiency of pasture-raised Nelore cattle during the backgrounding phase: interaction between water intake behavior, microclimate, and carcass composition. 2025. Dissertação - Faculdade de Medicina Veterinária e Zootecnia, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, 2025. The increasing global water scarcity imposes significant limitations on agricultural systems. In this context, beef cattle production requires greater water use efficiency as an essential condition to ensure productive sustainability and meet growing demand for food. This study aimed to estimate the residual water intake (RWI) of pasture-raised Nelore cattle and its association with microclimatic, behavioral, and carcass traits evaluated by ultrasound. A total of 77 Nelore males were used, with an initial average body weight of 309.4 ± 32.13 kg and an average initial age of 12.27 ± 1.13 months, evaluated across two experimental cycles (2023–2025). The animals were kept on Brachiaria brizantha cv. Marandu pasture, with electronic monitoring of water intake and drinking behavior. Ultrasound assessments were conducted at the beginning and end of the trial. Mean values for water intake (21.75 L/day), RWI (0 L/day), and water efficiency (22.92 L/kg ADG) were within the range reported in the literature for cattle under tropical conditions. A significant correlation (P0.05) were found among RWI classes for carcass traits. The selection of animals with greater water efficiency may not negatively affect carcass characteristics. Lower water consumption is related to shorter use of drinking fountains, as well as lower temperature and radiation. The results suggest that RWI is a promising tool for identifying more water efficient animals. Keywords: Beef cattle; carcass traits; ingestive behavior; microclimate; residual water intake; water efficiency.