Water footprint of a tropical beef cattle production system: The impact of individual-animal and feed management.

• The cow-calf phase was responsible for the greatest water footprint. • Water footprint values for individual-animal were too random. • The type of diet is an important mitigating action to reduce water footprint. • Animal performance and productivity influence green and blue water footprints. Beef cattle production systems hide an enormous variability of productive and management aspects that impact the water footprint value. To have a greater precision in decision making based on water footprint we should consider animal-individuality and propose managements solutions. The aims of this study were to calculate the water footprint for a tropical cattle production system and to evaluated the influence of each individual-animal performance and type of diet. This study calculated the volumetric water footprint (WF) in its three dimensions: green, blue, and grey. The reference units were: L kg LW-1 (liters per kg of live weight) and L kg CW-1 (liters per kg of carcass weight). This study used a population of 52 Nelore bulls (Bos taurus indicus). In the feedlot phase, cattle were divided into two subgroups by weight. Each subgroup was further divided into nutritional treatment groups: Co-product Feed Light Animals (COP_L) and Heavy (COP_H) and Conventional Feed Light Animals (CON_L) and Heavy (CON_H). Co-product diet consisted of corn silage + corn germ + citrus pulp + peanut meal. Conventional diet consisted of corn silage + maize + soybean meal. The type of diet did not significant affect carcass weight and live weight (p < 0.05). The individual-animal WF varied from 32,569 L - 29,923 L kg CW-1 and from 18,279 - 16,803 L kg LW-1. The weight of animals did not significantly affect performance indicators and water footprints for conventional diet (p < 0.05), but the green and total water footprints were significantly affected for co-product diets (p < 0.05). This information could be used to support improvements in policies and good practices for farmers and policy makers to enhance the beef water efficiency. The study also contributed to produce data that are still scarce in science about the use of water along beef chain and benchmark water footprint. The generation of information about meat water footprint and practices that can make the product more water efficient will have immediate value for decision making about present and future beef meat sustainability. [ABSTRACT FROM AUTHOR]