Faculdade de Zootecnia e Engenharia de Alimentos/USP -SP, Av.Duque de Caxias Norte, 225, Campus Fernando Costa- USP, CEP: 13635-900 Pirassununga, SP, Brazil.
Embrapa Pecuaria Sudeste, Rod. Washington Luiz km 234, São Carlos, SP 13560-970, Brazil.
Sci Total Environ. 2023 Dec 15;904:166733. doi: 10.1016/j.scitotenv.2023.166733. Epub 2023 Aug 30.
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.
本研究旨在通过提供人工遮荫并考虑当地条件和饲料种植来评估热带肉牛饲养系统的水、土地和养分效率。该研究在巴西的巴西农牧业研究公司东南家畜实验饲养场进行。48 头尼里-拉菲水牛公牛分为两组,一组有遮荫(GS),另一组没有遮荫(GWS)。记录了动物的体重、水摄入量和干物质摄入量。采用产品焦点评估法计算水足迹,考虑饲料生产和动物饮水所消耗的水。还评估了养分平衡和土地足迹。对于这两种处理方式,在马里亚纳种植的大豆和玉米第一季的作物情景导致了最低的水和土地足迹值。玉米是绿水消耗的主要贡献者。玉米第一季和第二季之间的用水效率降低。大豆粉的水足迹因生产地点而异。GWS 的平均蓝水消耗略高于 GS。就养分平衡而言,GS 处理表现出较低的氮和磷平衡值,表明这些元素的利用效率更高。提供人工遮荫被发现可以减少水足迹并提高养分利用效率。谷物生产的地点和玉米种植的时间被确定为影响水和土地足迹值的关键因素。