What must be included in the annual reports submitted to the USDA by institutions conducting animal research?

The inclusion of the number of animals used and significant regulatory changes in the annual reports submitted to the USDA is crucial due to the emphasis on transparency and accountability in animal research. This requirement ensures that the USDA can monitor compliance with the Animal Welfare Act. Reporting the number of animals used provides insights into the scale of research activities and helps track trends over time, which is important for addressing ethical considerations and improving animal welfare practices. Additionally, articulating any significant regulatory changes allows institutions to demonstrate awareness and responsiveness to evolving standards and policies that affect animal research, thereby fostering an environment of ethical scrutiny and continual improvement.

While the other options might contain relevant information regarding animal research, they do not address the specific reporting requirements set forth in the Animal Welfare Act, which focuses primarily on the quantitative aspects of animal usage and adherence to regulations.