Summary
The network of animal contact through movement
is an important factor in disease spread within and between populations.
The objective of this study was to characterise the spatial and temporal
distribution of bovine movements in Portugal, identifying local
and long-distance networks on the basis of geographical
proximity. Data were obtained from cattle movements in 2005, as recorded
in the national database for bovine identification and registration.
Geographic information systems were used to represent distribution
and flow of movements. Results did not detect any significant temporal
variation either in the number of movements or animals moved. Holdings
showed a higher density in the north where a larger number of movements
occurs. On the contrary, larger shipment lots tend to occur in the
south-central area. The greatest number of movements occurs inside
and between contiguous districts; animal movements mostly follow a
south-north pattern. Records analysed revealed that 60% of the animals
in circulation are beef cows under the age of 10 months (only
31% of the registered animals are younger than 12 months of age).
Keywords
Animals,
Cattle, Epidemiology, Geographic information system, Movement, Portugal,
Spatial analysis.
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