A descriptive exploration of animal movements within the United States cull sow marketing network.
Objective: Collect and describe data regarding sow movements within the US cull sow marketing network, and what implications those movements may have on disease introduction and dissemination within the United States. Materials and methods: Premise identification tags (PITs) were collected with the help of the US Department of Agriculture's Animal and Plant Health Inspection Service-Veterinary Services Brucellosis Laboratory. Collection occurred for a total of 6 months. From each PIT the management/sow identification (ID), premises ID, state, facility, and slaughter date were recorded. Participating production systems identified the cull dates of individual sows from their system. Results: A total of 17,493 PITs were collected. This study collected PITs from 32 states and 1211 unique premises IDs. Facilities received sows from a median (IQR) of 9.5 (12.5) states and 71 (79.25) unique premises each week. Sows traveled a median (IQR) distance of 472.7 (453.6) km with a maximum of 2812.8 km. A single premises delivered sows to 1, 2, or 3 or more slaughter facilities 59.7%, 33.4%, and 6.9%, respectively. Removal date from the farm of origin was available for 2886 (16.5%) individual sows. Of these, 66.1% were in the market channel for ≤ 3 days, 25% for 4 to 5 days, and 8.9% for > 5 days. Implications: These results suggest that the cull sow marketing channel provides an independent, but interconnected swine population that can maintain, expand, and transmit pathogens to the US swine herd. Control and elimination plans for novel, transboundary, and foreign animal diseases should include this population.