References

Explaining Why The Use Of Animals In Research Is Important

From the U.S. Government Principles For The Utilization And Care Of Vertebrate Animals Used In Testing, Research, and Training: 
“II. Procedures involving animals should be designed and performed with due consideration of their relevance to human or animal health, the advancement of knowledge, or the good of society.” 
http://grants.nih.gov/grants/olaw/references/phspol.htm#principle

From the Guide, 
“The following topics should be considered in the preparation of the protocol by the researcher and its review by the IACUC:

rationale and purpose of the proposed use of animalsa clear and concise sequential description of the procedures involving the use of animals that is easily understood by all members of the committeeavailability or appropriateness of the use of less invasive procedures, other species, isolated organ preparation, cell or tissue culture, or computer simulation (see Appendix A, Alternatives)”justification of the species and number of animals proposed; whenever possible, the number of animals and experimental group sizes should be statistically justified . . .

http://www.nap.edu/catalog.php?record_id=12910