Bava L, Sandrucci A, Zucali M, Guerci M, Tamburini A
Dipartimento di Scienze Agrarie e Ambientali, Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy.
Dipartimento di Scienze Agrarie e Ambientali, Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy.
J Dairy Sci. 2014 Jul;97(7):4579-93. doi: 10.3168/jds.2013-7530. Epub 2014 May 2.
The intensification process of the livestock sector has been characterized in recent decades by increasing output of product per hectare, increasing stocking rate, including more concentrated feed in the diet, and improving the genetic merit of the breeds. In dairy farming, the effects of intensification on the environmental impact of milk production are not completely clarified. The aim of the current study was to assess the environmental impacts of dairy production by a life cycle approach and to identify relations between farming intensity and environmental performances expressed on milk and land units. A group of 28 dairy farms located in northern Italy was involved in the study; data collected during personal interviews of farmers were analyzed to estimate emissions (global warming potential, acidification, and eutrophication potentials) and nonrenewable source consumption (energy and land use). The environmental impacts of milk production obtained from the life cycle assessment were similar to those of other recent studies and showed high variability among the farms. From a cluster analysis, 3 groups of farms were identified, characterized by different levels of production intensity. Clusters of farms showed similar environmental performances on product basis, despite important differences in terms of intensification level, management, and structural characteristics. Our study pointed out that, from a product perspective, the most environmentally friendly way to produce milk is not clearly identifiable. However, the principal component analysis showed that some characteristics related to farming intensification, such as milk production per cow, dairy efficiency, and stocking density, were negatively related to the impacts per kilogram of product, suggesting a role of these factors in the mitigation strategy of environmental burden of milk production on a global scale. Considering the environmental burden on a local perspective, the impacts per hectare were positively associated with the intensification level.
近几十年来，畜牧业的集约化进程表现为每公顷产品产量增加、饲养密度提高（包括日粮中使用更浓缩的饲料）以及品种遗传品质改善。在奶牛养殖中，集约化对牛奶生产环境影响的作用尚未完全明确。本研究的目的是通过生命周期方法评估奶牛生产的环境影响，并确定养殖强度与以牛奶和土地单位表示的环境绩效之间的关系。意大利北部的28个奶牛场参与了该研究；对农民个人访谈期间收集的数据进行分析，以估算排放（全球变暖潜势、酸化潜势和富营养化潜势）和不可再生资源消耗（能源和土地利用）。生命周期评估得出的牛奶生产环境影响与其他近期研究相似，且各农场之间差异很大。通过聚类分析，确定了3组农场，其特点是生产强度水平不同。尽管在集约化水平、管理和结构特征方面存在重要差异，但农场集群在产品基础上表现出相似的环境绩效。我们的研究指出，从产品角度来看，生产牛奶最环保的方式并不明确。然而，主成分分析表明，一些与养殖集约化相关的特征，如每头奶牛的牛奶产量、奶牛养殖效率和饲养密度，与每千克产品的影响呈负相关，表明这些因素在全球范围内减轻牛奶生产环境负担的策略中发挥了作用。从当地角度考虑环境负担，每公顷的影响与集约化水平呈正相关。
