Three environmental dimensions of beef cattle in tropical feedlot - Water, nutrients and land

This study aims to evaluate water, land, and nutrient efficiencies in a tropical beef feedlot system by providing artificial shading and considering local conditions and feed cultivation. The study was conducted at the Experimental Feedlot of Embrapa Southeast Livestock in Brazil. Forty-eight Nellore bulls were divided into two groups, with one group having shade (GS) and the other without shade (GWS). The animals' body weights, water intake, and dry matter intake were recorded. The water footprint was calculated using a product-focused assessment, considering water consumed in feed production and animal drinking. The nutrient balance and land footprint were also assessed. To both treatments, the crop scenario with soybean and corn first crop produced in Maringa resulted in the lowest water and land footprint values. Corn was the main contributor to green water consumption. The efficiency in water use for corn decreased between the first and second crops. The water footprint of soybean meal varied between production locations. GWS had slightly higher average blue water consumption than GS. In terms of nutrient balance, the GS treatment exhibited lower nitrogen and phosphorus balance values, indicating higher efficiency in the use of these elements. The provision of artificial shading was found to reduce the water footprint and improve nutrient use efficiency. The location of grain production and the timing of corn planting were identified as key factors influencing water and land footprint values.