The University of Iowa

Breeding - Rodent Breeding Colony Management (Policy)

Policy: The IACUC has provided a set of guidance documents (Policies, Guidelines, and Informational Sheets) for use when planning animal procedures at the University of Iowa. An exception to a Policy must be described and justified in the Animal Protocol and approved by the full IACUC at a convened monthly meeting.

Purpose: This policy establishes the parameters for appropriate breeding activities under the University of Iowa animal care and use program. This policy applies to all research personnel which perform breeding activities at the University of Iowa.

Background: The establishment of a rodent breeding colony may be necessary to develop an animal model that is not commercially available, or to produce young animals with specific ages or conditions which cannot be provided by a commercial breeding colony. Investigators developing a new spontaneous or induced mutant animal model might also need to maintain their own breeding colony because there is no alternative source for the animal model.

From a regulatory perspective, tracking all animals utilized in animal research protocols is closely scrutinized by extramural accrediting and oversight bodies. Breeding colonies receive particular attention, and require careful consideration of the justifications for the animal numbers used. Record keeping and colony management practices must demonstrate efforts to utilize animal subjects in ways that conserve genetic traits and are not wasteful.

 Maintenance of unnecessary breeding activities increases opportunities for infectious disease entry and transmission, genetic drift of inbred lines, reduces housing space for needed research activities, and increases expense to all investigators due to unrecovered costs of breeding activities. Investigators maintaining colonies exclusively to preserve a genetic line of rodents should consider other conservation strategies such as cryopreservation of ova, sperm and/or embryos.


  • Breeding of animals must be scientifically justified, and all breeding activities must be associated with a research project/protocol.
  • The production of otherwise available animals specifically for “cost saving” purposes is not permitted since these colonies unnecessarily occupy valuable space that could be used for animals not otherwise available and the actual costs involved include many significant overhead expenses that are subsidized by the University, and not recovered in per diem structures.
  • Permission to establish a breeding colony is granted on a case-by-case basis, with the most acceptable reasons for requiring a breeding colony listed below:
    • Experiments involving prenatal or early neonatal studies for which subjects would be too young to be procured commercially.
    • Breeding/backcrossing of genetically modified lines not available commercially.
    • Creation of new transgenic, knock-out or other genetically modified animals.
    • Breeding rare inbred lines not available commercially.
    • Production of fertilized gametes/embryos for molecular studies


Last Reviewed by the IACUC 8/10/2022