Laboratory of Biogeochemistry, Center of Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, CEP 13416-000 Brazil.
J Anim Sci. 2013 Apr;91(4):1811-8. doi: 10.2527/jas.2012-5603. Epub 2013 Jan 23.
No information regarding the management of manure from beef cattle feedlots is available for Brazil. To fill this knowledge gap, a survey of 73 feedlots was conducted in 7 Brazilian states. In this survey, questions were asked regarding animal characteristics, their diets, and manure handling management from generation to disposal. These feedlots finished 831,450 animals in 2010. The predominant breed fed was Nellore, with average feeding periods of 60 to 135 d. Corn was the primary source of grain used in the feedlot diets (76% of surveyed animals) with concentrate inclusion levels ranging from 81 to 90% (38% of surveyed animals). The most representative manure management practice was the removal of manure from pens only at the end of the feeding period. Subsequently, the manure was stored in mounds before being applied to crop and pasture lands. Runoff, mainly from rainwater, was collected in retention ponds and used for agriculture. However, the quantity of runoff was not known. Manure was composted for only 20% of the animals in the survey and was treated in anaerobic digesters for only 1% of the animals. Manure from 59% of the cattle surveyed was used as fertilizer, providing a cost savings over the use of synthetic fertilizers. Overall, chemical analysis of the manure before application to fields was conducted for the manure of 56% of the surveyed animals, but the exact quantity applied (per hectare) was unknown for 48%. Feedlots representing 48% of the surveyed animals noted similar or greater crop and pasture yields when using manure, rather than synthetic fertilizers. In addition, 32% mentioned an increase in soil organic matter. Feedlots representing 88% of the surveyed cattle indicated that information concerning management practices that improve manure use efficiency is lacking. Feedlots representing 93% of the animals in the survey reported having basic information regarding the generation of energy and fertilizer with anaerobic digesters. However, only 1 feedlot implemented this technology. In conclusion, the manure management evaluated in this study represents an important indirect economic benefit that was represented by decreased use of synthetic fertilizers in crops. However, little attention was given to the specific treatments and environmental impacts of handling manure. This survey provides information that should assist in the development of better research practices and broader application of future models.
巴西没有关于肉牛养殖场粪便管理的信息。为了填补这一知识空白，对巴西 7 个州的 73 个养殖场进行了调查。在这项调查中，询问了有关动物特征、饮食以及从产生到处置的粪便处理管理的问题。这些养殖场在 2010 年共饲养了 831450 头动物。饲养的主要品种是内罗尔牛，平均饲养期为 60-135 天。玉米是养殖场饲料中主要的谷物来源（占调查动物的 76%），浓缩物的含量范围为 81-90%（占调查动物的 38%）。最具代表性的粪便管理做法是仅在饲养期结束时从畜栏中清除粪便。随后，将粪便堆放在一起，然后施用于作物和牧场。主要来自雨水的径流被收集在滞留池中用于农业。然而，不知道径流的数量。调查中只有 20%的动物进行了粪便堆肥，只有 1%的动物进行了厌氧消化处理。调查中 59%的牛的粪便被用作肥料，比使用合成肥料节省成本。总体而言，在将粪便施用于田地之前，对 56%的调查动物的粪便进行了化学分析，但不知道 48%的粪便的具体施用量（每公顷）。代表 48%的调查动物的养殖场在使用粪便而不是合成肥料时表示，作物和牧场的产量相似或更高。此外，32%的人提到了土壤有机质的增加。代表 88%的调查牛的养殖场表示，缺乏有关提高粪便利用效率的管理实践的信息。调查中 93%的养殖场表示对利用厌氧消化器产生能源和肥料的基本信息有所了解。然而，只有 1 个养殖场实施了这项技术。总之，本研究评估的粪便管理代表了一个重要的间接经济效益，减少了作物中合成肥料的使用。然而，很少关注粪便处理的具体处理和环境影响。本调查提供的信息应有助于制定更好的研究实践和更广泛地应用未来的模型。
