Effect of management system and dietary seasonal variability on environmental efficiency and human net food supply of mountain dairy farming systems-Supplement Material

Although mountain dairy cattle farming systems are pivotal for the economy, as well as on social- and environmental aspects, significantly contributing to the rural development which is currently strongly prioritized in the common EU agricultural policy, they are also increasingly criticised for having relatively high environmental impacts per kg of product, such as the production of greenhouse gas emissions. Consequently, the aim of this study was to assess and compare the environmental efficiency of two common alpine dairy farming systems, with focus on the effects of grazing, considering the seasonal variability in feeding at individual cow level and farm management over a three-year period. This study focuses on alpine farming systems but can be considered to represent well other topographically disadvantaged mountain areas. An intensively managed and globally dominating production system (high-input), aiming at high milk yield through relatively intensive feeding and the use of the high-yielding dual-purpose Simmental cattle, permanently confined in stables, was compared to a forage-based production system (low-input), based on seasonal grazing and the use of the autochthonous dual-purpose breed Tyrolean Grey. For the present analysis, a dataset with information on feed intake and diet composition as well as animal productivity at individual cow level, and farm management data based on multiyear data recording was used. Four impact categories were quantified for three consecutive years: Global Warming Potential (GWP), Acidification Potential (AP), Marine Eutrophication Potential (MEP), and Land Use (LU, m2yr and Pt, with the latter additionally considering the Soil Quality Index). Besides being attributed to 1 kg of fat and protein corrected milk (FPCM), these impact categories were also related to 1 m2 of on-farm area. Due to limited agronomic options beyond forage production and pasture use in alpine regions, net provision of protein was calculated for both farming systems to assess food supply and quantify the respective food-feed competition. Overall, the low-input farming system had greater environmental efficiency in terms of MEP per kg FPCM, as well as MEP and AP per m2 than the high-input system. LU was found to be consistently higher for the high-input than for the low-input system, the GWP per kg of FPCM was lower for the high-input system. Additionally, pasture access had a significant effect on the reduction of environmental impacts. Lastly, the net protein provision was negative for the high-input system and marginally positive for the low-input system, indicating a lower food-feed competition for the latter.

尽管山地奶牛养殖业对于经济、社会和环境方面均具有关键性作用，对当前受到高度重视的欧盟共同农业政策中优先推动的农村发展做出了显著贡献，然而，由于其单位产品具有较高的环境影响，如温室气体排放，因而亦日益受到批评。鉴于此，本研究旨在评估和比较两种常见的阿尔卑斯山地奶牛养殖系统的环境效率，重点关注放牧的影响，并考虑个体奶牛在不同季节的饲料摄入以及农场管理在三年间的季节性变化。本研究聚焦于阿尔卑斯山地养殖系统，但亦可视为其他地形劣势的山地区域的有力代表。一种密集管理且在全球范围内占据主导地位的生产体系（高投入），旨在通过相对密集的饲养和利用高产双用途的西门塔尔牛，实现高牛奶产量，牛只被永久性地关押在牛舍中，与一种基于饲料的生产体系（低投入）进行了比较，后者基于季节性放牧和利用本地双用途的特罗伊尔灰牛。为了进行当前分析，使用了一个包含饲料摄入量和饲料组成以及个体奶牛生产力和基于多年数据记录的农场管理数据的数据库。在连续三年的三个影响类别中进行了量化：全球变暖潜力（GWP）、酸化潜力（AP）、海洋富营养化潜力（MEP）和土地利用（LU，以m2yr和Pt表示，其中后者还考虑了土壤质量指数）。除了将这些影响类别归因于每千克脂肪和蛋白质校正牛奶（FPCM）外，它们也与每平方米的农场面积相关。由于阿尔卑斯地区农业选项有限，仅限于饲料生产和放牧，因此计算了两种养殖系统的蛋白质净供应量，以评估食品供应并量化相应的食品饲料竞争。总体而言，在每千克FPCM的MEP以及MEP和AP每平方米方面，低投入养殖系统在环境效率上优于高投入系统。土地利用在低投入系统中的水平始终高于高投入系统，每千克FPCM的GWP在高投入系统中较低。此外，牧场可及性对减少环境影响具有显著影响。最后，高投入系统的蛋白质净供应量为负，而低投入系统则微弱为正，这表明后者在食品饲料竞争方面具有较低水平。