Suchergebnisse

[EN] Livestock housing is one of the main sources of ammonia (NH3) emissions from agriculture. Different management and environmental factors are known to affect NH3 emissions from housing systems. The aim of this study was to quantitatively define the effect of temperature, wind speed, relative humidity, and ventilation rate on NH3 release rates from dairy cattle housing by conducting a meta-analysis of published scientific results. A literature survey was performed to review studies published before January 2018 that have identified statistical relationships between NH3 emissions and environmental factors such as air temperature, wind speed, relative humidity, or ventilation rate in dairy cattle housing. Experimental values were related using a mixed model analysis in order to analyse the effect of environmental factors on NH3 emissions. For this exercise, a total of 19 peerreviewed papers were considered and 27 different relations between air temperature and NH3 emissions were used for the analysis. A significant effect of air temperature inside the barn and ventilation rate on NH3 emissions was observed. Results showed that NH3 emissions increased linearly with increasing air temperature (ºC) inside the barn by 1.47 g [NH3] cow 1 d 1 when temperature increased by one degree. For ventilation rate, an increase of 100 m3 h 1 cow 1 led to an increase in NH3 emissions of 0.007 g [NH3] cow 1 d 1 . The equations obtained in this work might help to provide information on NH3 barnrelated emissions behaviour under these environmental conditions, bearing in mind that other source of emissions such as diet composition and animal performance might be also affected by climate changes. ; This study is part of the project OPTIBARN and was financially supported by the Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria through the research grant 618105 FACCE Era Net Plus - Food Security, Agriculture, Climate Change ERA-NET plus. This work has been also funded by the Basque Government through the BERG ...

Altres ajuts: Basque Government to E.G (IT1022-16), A.A (IT1365-19), and L.J.R.B. (IT944-16) ; Unidad de excelencia María de Maeztu CEX2019-000940-M ; Pastoral systems face increasing pressure from competing global markets, food sector industrialization, and new policies such as Europe's post-2020 Common Agriculture Policy. This pressure threatens the use of extensive sheep-grazing systems in mountain areas of low productivity but high natural value. Using information gathered at a long-term research setting in a mountainous area of the Basque Country (northern Spain), we assessed the multiple benefits of extensive dairy sheep grazing systems from multiple perspectives using indicators pertaining to ecological, socio-economic, and food quality domains. In this way, we address the benefits that would be lost if sheep grazing abandonment persists in mountain regions. Our results show that the benefits of extensive dairy sheep grazing in the research area include the production of healthy and high-quality foods and multiple ecological benefits including biodiversity conservation. Extensive dairy sheep grazing also contributes to rural development by generating employment and income in marginal, low-productivity lands that can support few economic alternatives. In particular, we found that sheep farmers who produce high-value products, such as cheese, have enhanced their economic profitability and are less dependent on public subsidies. However, careful attention to sustainable practices, support for new generations of farmers, and streamlined supply chains are required. These would contribute to ensure socio-economic benefits for farmers, avoid the ecological costs associated with grazing abandonment, and enhance ecosystem services for the whole society.