Assessment of cattle traceability using electronic identification and digital movement reporting in simulated United States cattle movement networks

Introduction In a disease outbreak, animal health officials in the United States (US) must identify the diseased and at-risk animals and implement control measures. For rapidly-spreading diseases, electronic identification (EID) of animals and digital reporting (DR) of animal movements are likely needed for rapid, effective tracing and control measure implementation. Currently, the US does not require all cattle movements to be reported and only requires official EID of dairy cattle and some classes of beef cattle. This project created a simulated national cattle movement network to assess the traceability of farms with various levels of EID and DR. Methods A 30-day, simulated US cattle movement network was generated. In the network, farms, markets, processors, and other premises are nodes and movements between premises are edges. A random sample of 100 cow-calf farms, 100 markets, and 100 feedlots were selected from the full network to be “farms of interest” (FOIs) to assess traceability to their contact farms. To generate traceable networks, EID status was assigned to source nodes and DR status assigned to destination nodes using a binomial process. The EID and DR probabilities began with a baseline level that represented the estimated current usage in US cattle, and improved across increasing EID and DR probabilities to the highest level wherein 75% of all beef cattle farms tagged outgoing movements and 90% reported incoming movements. A movement was traceable and included in the traceable network when the source tagged and the destination reported. Results and discussion In the baseline scenario, there were zero traceable incoming contacts across all three farm types tested. As EID and DR increased, the traceability increased. With the highest level of EID and DR, the average percent of contacts traceable was 83.56% for cow-calf FOIs, 86.5% for market FOI total contacts, and 75.63% for feedlot FOIs. These results support increasing EID tag use and DR to enable rapid, effective tracing and provide implementation targets to improve traceability. The current EID and DR adoption is likely insufficient for effective electronic tracing and higher usage is needed to facilitate rapid tracing.