A process of agricultural data disaggregation is developed to address the lack of updated disaggregated data concerning main livestock categories at subregional and county level in the Alentejo Region, southern Portugal. The model developed considers that the number of livestock units is a function of the agricultural and forest occupation, and data concerning the existing agricultural and forest occupation, as well as the conversion of livestock numbers into normal heads, are needed in order to find this relation. The weight of each livestock class is estimated using a dynamic process based on a generalized maximum entropy model and on a crossentropy minimization model, which comprises two stages. The model was applied to the county of Castelo de Vide and their results were validated in cross reference to real data from different sources. 1. Introduction Disaggregated statistical information is necessary to have a correct analysis of spatial patterns inside each country, but data on agricultural and forest occupation and production are frequently found only at national and subnational level [1–4], and oftentimes this problem does not have an appropriate and accurate solution. In Portugal, southern Europe, apart from the general lack of data on agricultural and forest occupation, there is a need for up-to-date data on livestock numbers [2]. Only the General Agricultural Census (GAC), conducted by the National Institute of Statistics (NIS) every 10 years, features information at disaggregated level by subregion, county, and parish. The other information sources display information merely according to agrarian regions and NUTS II [5, 6]. Even the different agents operating in the territory do not have more detailed data, and only the health veterinary entities have some more accurate data for nowadays, which is not accessible to all. However, planning and devising of a clear and sustainable rural development policy call for the availability of disaggregated information [4], at least when it comes to the numbers of livestock intended for breeding, mainly in regions where these variables have a great importance for the farmers’ income. After the entrance of Portugal into the European Union, the Alentejo region, southern Portugal, has come under the influence of different policies and as a consequence there are several inland rural areas with problems and in decline, as well as the extensification of agricultural activities [7]. In this region, the importance of livestock breeding activity is unquestionable [8]. A particular county where there is a tendency
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