**1. Introduction**

Organic livestock farm numbers have sharply increased in recent years [1] as an adaptive response for increasing farm profitability (through subsidies and price premiums). However, before implementing any production systems, an analysis of the similarities and differences between both the current and the potential new farm configurations should be carried out, since it will provide a wider view of the chances of success after the change.

For this purpose, the methodological process of farm characterisation is essential as it allows in-depth understanding of the operation of livestock production systems, which is key to improving their management, economic performance and overall sustainability. Thus, Rodríguez et al. [2] stated that farm viability relies on specific management practices that are suitable for the specific socioeconomic and environmental context of the farm, and this should be based on the knowledge of the characteristics and performance of the production systems.

Subsequently, several researchers have conducted studies for characterising farms according to various parameters. Some authors have focused on livestock species reared on the farms. Thus, different authors [3–10] have studied and characterised beef cattle farms by means of descriptive and/or cluster analysis on the basis of technical, structural, economic and/or social indicator. However, to our knowledge, there are no available studies that comparatively characterise organic and pasture-based or low-input conventional beef cattle farms, contextualizing such analysis within the evolution of the production systems under study. We therefore believe that this is a particularly appropriate time to conduct the present study. This would be of even more interest if the farms studied were located in complex agro-ecosystems with great value and externalities from the socio-economic and environmental points of view.

The present study was carried out with the following aims: (i) to shed light on the gap of knowledge existing due to the lack of studies that compare the characteristics of conventional and organic beef cattle farms and (ii) to find similarities and differences between organic and low-input conventional beef cattle farms. For this purpose, a characterisation (technical management, structure and economic performance) of the farms located in the '*dehesa*' was carried out.
