Final answer:
The IACUC values protocol items that justify the use of animals, minimize their pain and distress through refined procedures, and reduce the number of animals used, adhering to the three R's principle: replace, refine, and reduce.
Step-by-step explanation:
Items that are helpful to the Institutional Animal Care and Use Committee (IACUC) when reviewing an animal protocol include the justification for the use of animals, refinement of procedures to minimize pain and distress, and strategies to reduce the number of animals used. The IACUC is responsible for ensuring that the NIH guidelines are followed, which include considering the three R's of ethical animal research: replace, refine, and reduce. Proposals should detail how the researchers plan to replace animals with nonliving models or less sentient organisms when possible, refine proceedings to minimize suffering, and reduce the quantity of animals required for valid results.