Mapping U.S. cattle shipment networks: Spatial and temporal patterns of trade communities from 2009 to 2011

Abstract

The application of network analysis to cattle shipments broadens our understanding of shipment patterns beyond pairwise interactions to the network as a whole. Such a quantitative description of cattle shipments in the U.S. can identify trade communities, describe temporal shipment patterns, and inform the design of disease surveillance and control strategies. Here, we analyze a longitudinal dataset of beef and dairy cattle shipments from 2009 to 2011 in the United States to characterize communities within the broader cattle shipment network, which are groups of counties that ship mostly to each other. Because shipments occur over time, we aggregate the data at various temporal scales to examine the consistency of network and community structure over time. Our results identified nine large (>50 counties) communities based on shipments of beef cattle in 2009 aggregated into an annual network and nine large communities based on shipments of dairy cattle. The size and connectance of the shipment network was highly dynamic; monthly networks were smaller than yearly networks and revealed seasonal shipment patterns consistent across years. Comparison of the shipment network over time showed largely consistent shipping patterns, such that communities identified on annual networks of beef and diary shipments from 2009 still represented 41-95% of shipments in monthly networks from 2009 and 41-66% of shipments from networks in 2010 and 2011. The temporal aspects of cattle shipments suggest that future applications of the U.S. cattle shipment network should consider seasonal shipment patterns. However, the consistent within-community shipping patterns indicate that yearly communities could provide a reasonable way to group regions for management.

Burkholderia mallei : The dynamics of networks and disease transmission

“…The establishment of network communities is an emerging approach that has been used to describe species movement patterns (Gorsich et al., ), disease spread and prevention (Aragão et al., ; Kao, Green, Johnson, & Kiss, ; Motta et al., ), and implementation of target vaccination or as part of surveillance for Foot‐and‐Mouth Disease at the national level (MAPA, ). The identified communities may have a direct impact in the decision taken by the local stakeholders, such as the OVS.…”

“…Furthermore, if the state official veterinary authorities (SEAPI, ) decides on the implementation of movement restrictions in order to improve surveillance and improve horse health in the state of Rio Grande do Sul, it is recommended to restrict movements within each community (Figure ). The maps of the communities found in our study were used to show the greatest equine trade areas and offer a valuable guide for the zoning of the horse trade in the studied area (Gorsich et al., ; Grisi‐Filho et al., ).…”

“…The establishment of network communities is an emerging approach that has been used to describe species movement patterns (Gorsich et al, 2016), disease spread and prevention (Aragão et al, 2017;Kao, Green, Johnson, & Kiss, 2007;Motta et al, 2017) Sul, it is recommended to restrict movements within each community ( Figure 6). The maps of the communities found in our study were used to show the greatest equine trade areas and offer a valuable guide for the zoning of the horse trade in the studied area (Gorsich et al, 2016;Grisi-Filho et al, 2013).…”

Estimating and exploring the proportions of inter- and intrastate cattle shipments in the United States

“…We selected ten states to focus on, California, Colorado, Iowa, Minnesota, North Carolina, Nebraska, New York, Pennsylvania, Tennessee, and Texas. These states were selected because they were found in previous work to be important in the cattle shipment network (Gorsich et al, 2016), and they represent major geographic regions in the U.S. The survey targeted cattle experts with deep knowledge of the cattle industry, including cooperative extension professors, state veterinarians, veterinary medical experts, epidemiologists, cattleman's association leadership, and USDA personnel.…”

“…In the U.S., the most extensive data on cattle shipments are the Interstate Certificates of Veterinary Inspection (ICVIs) that record interstate (between-state) shipments of livestock (Buhnerkempe et al, 2013;Portacci et al, 2013;Gorsich et al, 2016). These data have been used to build a national model for cattle shipments, called the United States Animal Movement Model (USAMM), that can be used to understand general cattle shipment patterns in the U.S. (Buhnerkempe et al, 2013;Lindström et al, 2013) and have also been used to predict movement of at-risk cattle (Grear et al, 2014;Gorsich et al, 2018).…”