Investigating on the environmental sustainability of animal products: The case of organic eggs

The organic farming of laying hens is experiencing a growing trend in Italy, following an increase in consumer demand for organic eggs. The present study aimed to investigate the environmental performance of organic egg production for the first time in the Italian context. To this end, the Life Cycle Assessment (LCA) of organic egg production in a farm rearing laying hens located in Northern Italy was performed. The analysis was carried out in a cradle to farm gate perspective, with 1 kg of eggs selected as functional unit. Primary data relating to animal performances and resources consumed was collected on site, and subsequently integrated with secondary data, including estimates of manure-related emissions. In order to model in a representative way the organic feed consumed, data relating to typical cropping systems of the country has been used for the various ingredients, keeping the organic production method specifications into account. Inventory data was then converted on an annual basis and characterized using the ILCD method, and twelve impact categories were assessed. Moreover, the influence on impact results of different allocation choices and efficiency in terms of hen-day egg production were explored with a sensitivity analysis. The main environmental burden for organic egg production showed to be feed production and supply, with a share ranging from 49% to 87% over all the evaluated impact categories. Other hotspots are pullets rearing, responsible for a share between 10 and 14% over all categories, and manure-related emissions, which weighed significantly for PM (35%), TA (39%) and TE (39%). A value for CC of 1.56 kg CO2 eq/kg shelled eggs was obtained, thanks to good production performances together with some benefits given by organic feed use, particularly the avoidance of mineral fertilizer consumption and of land use change related emission. At the same time, the results show clearly that environmental improvements should be sought primarily in the same feed area. This must be done both on-farm, which was highlighted also by the sensitivity analysis on hen-day egg production, and at the supply chain level, acting on the impact related to crop production and pullets rearing phases. Starting from the results, some environmental weaknesses and strengths of organic farming have been discussed. Future studies must further investigate the impact of this rearing system in a wider perspective and explore possible scenarios of mitigation practices.