Abstract: A BRDC sign detecting system includes: a processor, and a memory storing program instructions that cause the processor to obtain, with respect to a bovine developing bovine respiratory disease complex (BRDC) within a time period required for a fattening process, data indicating a condition of the bovine during a predetermined time period in which the bovine did not yet develop the BRDC, and obtain data indicating a condition, during a predetermined time period, of a bovine that has not developed BRDC perform machine learning with respect to a correspondence relation between the obtained data indicating the condition during the predetermined time period and information indicating whether BRDC is developed, and infer, by inputting data indicating a condition of a new bovine during the predetermined time period into a learned model generated by performing the machine learning, information indicating whether the new bovine will develop BRDC and output an inference result.