The stock of pigs shows the total number of pigs in Denmark. The statistics are published quarterly and are primarily used as base for forecasts of pigs for slaughter and forecasts for the total number of pigs. The Statistic are used in connect with different economic and environment estimations and analyses. The stock of pigs have been estimated after different methods since 1915. Last change was April 1, 2018, which has minimal significance for the comparison over time. The difference between the new method and the old one is below 1 per cent.
The statistics are publics every quarter in the Stat Bank, as "Pigs total" and " Sows total" . The unit of measure is number of pigs in thousand number. The stock of pigs is divided into 10 sub-groups. The data series with the total stock of pigs (pigs, total) are seasonally adjusted. The pig survey is a sample survey, The population includes all active farms in Denmark and is integrated in the Statistical Business Register (ESR), which is kept by Statistics Denmark, and which is registered with pigs in the Central Livestock Register (CHR). Survey date is the 1st of each quarter.
Data for the pig survey is collected by means of web questionnaires or by means of the system to system solution ArgoSofts Winsvin. A sample of 2.200 holding with pigs according to the livestock register is selected. The answers are validated for unrealistic values and next the sample is extrapolated to the total population of all farms with pigs. The survey is a sample survey divided into groups (strata) by the size of pigs and types of pigs on the single holding.
The pigs survey is of great interest to EU, the Ministry of Environment and Food, The Danish Association of Slaughterhouses and others farmer´s organizations, but also students and interested people in general. The most important purposes of pig surveys are to provide a basis base for forecasts of pigs for slaughter. The statistics are used in financially and environment studies. There are no examination of the uses satisfaction, but the impression is, that most users are satisfied with the statistics.
The greatest factor of inaccuracy is updating and matching of the different registers. The relative standard deviation - sampling errors - for pigs is 0.5 per cent to 1.5 per cent. A maximum of 2 per cent has to be observed to meet EU's requirements. As part of a quality assessment statistical errors are calculated for all variables.
The figures are usually published without delay in relation to the scheduled data, however with some exceptions in 2012 and 2013.
The pig surveys have been conducted in their present form since April 1974, but the number of pigs have been conducted at varying points in time and frequency since 1915.
New figures for January and July are published in a news letter New from Statistics Denmark, and all figures can be found in the Statbank. SVIN.