Table 1.
Description of the independent variables included in the analysis
| Name | Description | Source | Type |
| Demographics | |||
| TVETNET | Holding type. Reclassified into three categories: beef, dairy, other (including mixed herds). | VETNET. Animal Health Information System of the State Veterinary Service (SVS) | Categorical |
| CATSHE | Mixed holding (cattle and sheep). | Agricultural Census 2004 | Binary |
| TCTS | Holding type. Only two types of holdings appear in the final study population: agricultural holdings with land and landless keeper. Other holding types as in CTS database do not appear because markets, abattoirs, Artificial Insemination Centres and show grounds have not been included in the study population. | Cattle Tracing System (CTS) | Binary. |
| FARMA | Total area farmed in Ha. | Agricultural Census 2004 | Numeric |
| OPENCLOSED | Registered movements on/off in CTS during 2004. If none was recorded, it was considered closed. If at least one movement either on or off was registered, it was considered open. | CTS | Binary |
| HERSIZE | Herd size was estimated by combining the information available in two data sources. It is the number of cattle present at the time of conducting the Agricultural Census or when VETNET database was updated | VETNET and Agricultural Census (2004) | Numeric |
| Densities | |||
| CATDENSITY | Average number of cattle in the area surrounding the holding's location. The kriged surface using HERSIZE is a "smoothed" value of the cattle population in the area where the holding is located. This is obtained by generating a cattle population density surface from interpolation of herd size numbers between the holding point locations. It was calculated by using ordinary kriging based on a spherical semivariogram using ArcGIS 9 (© ESRI). | HERSIZE | Numeric |
| SHEDENCEN | Density of sheep in the area where the holding is located. This is calculated by assigning to each location the total sheep population of sheep in the 5 km2 grid cell where the holding is located. | UKBORDERS-EDINA-Agricultural Census 2004 | Numeric |
| CATBUF5 | Density of cattle holdings in the buffer area of 5 km radius (78.5 km2) surrounding the point location of each holding of the study population. | Agricultural Census 2004, CTS and Farmfile | Numeric |
| Environmental | |||
| ADDPOST | Number of addresses in the post code where the holding is located. | UK Postcode Directory-National Statistics | Numeric |
| POPCAS | Number of total human population in the Census Area Statistics (CAS) where the holding is located. | UK Census 2001-National Statistics. 2001 Census Aggregate Outputs. Economic & Social research Council (ESRC). | Numeric |
| SOILCAT | 24 soil classes according to NATMAP soilscapes have been aggregated into four main soil types: Combinations of loamy soils, combination of acid soils, combination of freely draining soils and other types (peat soils, salt marsh, sand dune, etc.). | NATMAP soilscapes for Wales. National Soil Resources Institute (NSRI) – Cranfield University. Silsoe. Bedford. | Categorical |
| TEXTCAT | Three classes of soil texture according to NATMAP soilscapes: loamy, peaty and sandy. | NATMAP soilscapes for Wales. National Soil Resources Institute (NSRI) – Cranfield University. Silsoe. Bedford. | Categorical |
| DRAINCAT | Six classes of soil drainage according to NATMAP soilscapes and re-classified into four types: freely draining, impeded and slightly impeded drainage, surface wetness/naturally wet and variable. | NATMAP soilscapes for Wales. National Soil Resources Institute (NSRI) – Cranfield University. Silsoe. Bedford. | Categorical |
| FERTCAT | Ten classes of soil fertility according to NATMAP soilscapes re-classified into four types: high, moderate, low and lime-rich. | NATMAP soilscapes for Wales. National Soil Resources Institute (NSRI) – Cranfield University. Silsoe. Bedford. | Categorical |
| LANDNATMAP | Sixteen land classes according to LANDNATMAP re-classified into three types: combinations of arable land, combinations of grassland and other (moorland, forestry, etc.) | NATMAP soilscapes for Wales. National Soil Resources Institute (NSRI) – Cranfield University. Silsoe. Bedford. | Categorical. |
| LANDCOVER | Ten classes: improved grassland, coniferous woodland, semi-natural grass, broad-leaved/mixed woodland, mountain/heath/bog, arable and horticultural, built-up/gardens, standing open water, oceanic and coastal. Source: 1 km grid raster data with aggregate classes and sub-classes, | Land Cover Map 2000: Centre for Ecology & Hydrology. | Categorical |
| HABICAT | Twenty classes of habitats according to NATMAP soilscapes and re-classified into four types: combinations of pasture and woodlands, combination of grassland and grass moors, combination of wet areas and other (coastal salt marsh, sand dune vegetation, etc.). | NATMAP soilscapes for Wales. National Soil Resources Institute (NSRI) – Cranfield University. Silsoe. Bedford. | Categorical |
| TOTRAIN | Total rainfall in 2003. 5 km grid monthly mean rainfall | Mean rainfall and temperature data (1999–2004). Geographic Information Unit- DEFRA- authorised by the Met Office | Numeric |
| AVETEMP | Annual average surface temperature in 2003. 5 Km grid monthly mean temperature | Mean rainfall and temperature data (1999–2004). Geographic Information Unit- DEFRA- authorised by the Met Office | Numeric |
| 5KMAONB | Within or at less than 5 Km to an Area of Outstanding Natural Beauty (AONB). | Protected sites datasets Country side Council of Wales | Binary |
| 5KMNNR | Within or at less than 5 Km to a National Nature Reserve (NNR). | Protected sites datasets Country side Council of Wales | Binary |
| 5KMLNR | Within or at less than 5 Km to a Local Nature Reserve (LNR). | Protected sites datasets Country side Council of Wales | Binary |
| WITHISSSI | Within a "Site of Special Scientific interest" (SSSI). | Protected sites datasets Country side Council of Wales | Binary |