National Bio and Agro-Defense Facility Act of 2019 This bill provides statutory authority for the Department of Agriculture (USDA) to act through the National Bio and Agro-Defense Facility to provide integrated research, development, and response capabilities to defend U.S. agriculture and food against bio- and agro-terrorism threats. Specifically, the bill requires USDA to use the facility to implement research and development objectives to (1) develop veterinary countermeasures for emerging foreign animal diseases and animal transboundary diseases; (2) provide advanced test, diagnostic, and evaluation capability for threat detection, vulnerability assessment, and veterinary countermeasure assessment for animal and zoonotic diseases; and (3) assist with the development, and address vulnerability assessments, of the agriculture and food sectors. USDA must also evaluate the work of the facility and publish an unclassified strategic research plan for the facility based on risk and threat assessment.