Search

Life Cycle Assessment (LCA) is an internationally accepted and broadly used tool to quantify the environmental impacts (EIs) of food across the whole production chain. So far, studies analyzing farms over a series of consecutive years have not been available, but are necessary to ensure a better representativeness of the results. Therefore, the aim of the current study was to investigate the development of EIs caused by milk production over a decade. Therein, the EIs were analyzed using two different datasets from Northern German farms. Firstly, the maximum number of farms available per year (n = 422-608, total dataset) was applied to document annual fluctuations in structural or rather economic conditions. Secondly, all farms providing data over ten years (n = 113, continuous dataset) were included in order to examine the development of the farms themselves. To investigate the influence of the soil type on the level of EIs, the farms were grouped in the regions sandy heathland (Heath), marshland (Marsh) and eastern hillside region (Hill). A "cradle to farm-gate" LCA was performed for every farm and year from 2004 to 2013, respectively. 1 kg energy-corrected milk yield (ECM) was defined as the functional unit. Climate change (GWP), freshwater eutrophication (FE), terrestrial acidification (TA) and agricultural land occupation (ALO) were chosen as environmental impact categories. The GWP ranged from 1.26 to 1.56 kg CO2 eq., the TA from 0.0240 to 0.0298 kg SO2 eq., the FE from 0.000258 to 0.000334 kg P eq. and the ALO from 0.93 to 1.19 m(2)/a. There was no general tendency of a consistent increase or decrease in EIs throughout the investigated decade. However, the level of EIs varied more frequently between years than between regions. In the year 2012, in most cases EIs were significantly higher in the Marsh compared to the other two regions.

Sample sizes of welfare assessment protocols must warrant to reflect prevalences on-farm properly - regardless of farm size. Still, solely a fixed sample size was specified for the Welfare Quality(R) protocol for sows and piglets. The present study investigated whether animals may be assessed from only one body side as applied in the protocol and whether the pre-set sample size of 30 animals mirrors the prevalences of the animal-based indicators on-farm in the gestation unit considering different farm sizes. All indicators were assessed for both sides of an animal's body by one observer on 13 farms in Germany, which were visited five times within 10 months. The farm visits were treated as independent since different animals were housed in the gestation units. The number of sows in the gestation units varied between 18 and 549 animals. The comparison of sides was carried out calculating exact agreement between animals' sides and a Wilcoxon signed-rank test (W). The results signified that it is sufficient to assess the animal from one side (exact agreement: 88.3% to 99.5%, except for bursitis (70.0%); W: P-values 0.14 to 0.92). However, if side preferences existed in the indicator bursitis a potential bias must be considered. In the following, the sample size was evaluated by comparing samples' prevalences against true prevalence, that is, the prevalence of all observed animals in the gestation unit in each farm visit. Therefore, subsets of data were generated by applying simple random sampling without replacement. The samples randomly included the animals' right or left sides. Linear regression was rated as appropriate provided: coefficient of determination R-2 >= 0.90, slope = 1 and intercept = 0 signifying exact agreement. The results revealed that the sample size required by the protocol and the application of calculation formulas are solely appropriate to mirror the prevalences of frequent indicators in the gestation unit, for example, bursitis (mean preval