The European Union states that member states must hold fixed quarterly statistics on the number of cattle, either through surveys or from quality, contrasted administrative sources.
Until 2011, the technique used by the Ministry of Agriculture, Livestock, Fisheries, Food and the Natural Environment (DAAM) and the Ministry of Agriculture, Food and the Environment (MAGRAMA) was a survey of farm owners, but from this year on, it has been agreed that this will be replaced by the use of administrative records, specifically the General Register of Individual Animal Identification (RIIA) and the General Register of Cattle Movement (REMO). This decision is taken jointly throughout the state after finding that the statistical information they provide is of a quality and reliability equal or superior to the surveys. This change in methodology represents significant progress in administrative simplification, cost reduction and significant improvement in the quality of results.
It must be remembered, however, that this methodological improvement causes a break in the time series data, which is larger the more the data is broken down. Therefore, the results for 2011 and earlier that are broken down by categories of animals cannot be compared with those of later years, since the changes observed are due to methodological change and not real differences.
Unavailable information is represented using the symbol ":". When the value is lower than that of the minimum unit to be able to estimate the statistical operation or if it effects statistical confidentiality, the symbol used is "..".