Combined spatial and network analyses of British pig movement data
Research partner: Scottish Agricultural College (SAC)
Sponsor: AHDB Pork-funded studentship (Diogo Marques)
Project duration: 2009–2012
Aims and objectives
- To identify and characterise the “active” British pig holdings regarding their demographic, spatial and network structure
- To explore the spatial and network distribution of three endemic conditions: Enzootic Pneumonia, Ascariosis and Sarcoptic Mange
- To assess the weighted contribution of farm spatial and network characteristics to the prevalence of Enzootic Pneumonia, Ascariosis and Sarcoptic Mange.
Due to time constraints, however, the project only focused on the first objective: Identification and characterisation of the pig demographic, spatial and network structure.
- This project has shown the value of movement data for the characterisation of denominator data ie number of active pig holdings, and the different types of producers
- The results show that there was an interconnection between the different types of producers in terms of movements, especially for the unexpected movements between large producers (believed to belong to quality assurance schemes and therefore with a higher biosecurity) and small producers (believed to have a lower biosecurity status and therefore more prone to introduction and spread of undiagnosed disease)
- The network analysis showed that medium producers had a higher proportion of movements to small and large producers than the inverse
- It is therefore plausible that medium producers may represent a bridge between the large and small producers of the pig industry, potentially allowing undiagnosed pathogen to spread throughout the industry
- A risk-based approach is recommended for consideration within future monitoring programmes, particularly for exotic disease.