Standard on Environmental Enrichment for Research Animals

Title

University of North Carolina at Chapel Hill Standard on Environmental Enrichment for Research Animals

Introduction

Purpose

The standards and procedures described below provide guidance to all researchers and animal handlers for the environmental enrichment of research animals. Environmental enrichment is required by federal regulation, and is essential to the psychological well-being of research animals.

The Guide for the Care and Use of Laboratory Animals (NRC, 2011) states that, “The primary aim of environmental enrichment is to enhance animal well-being by providing animals with sensory and motor stimulation, through structures and resources that facilitate the expression of species-typical behaviors and promote psychological well-being through physical exercise, manipulative activities, and cognitive challenges according to species-specific characteristics.”

The Guide further states that, “Well-conceived enrichment provides animals with choices and a degree of control over their environment, which allows them to better cope with environmental stressors.”

Scope of Applicability

This Standard provides information about the environmental enrichment program for research animals at the University of North Carolina at Chapel Hill ("UNC-Chapel Hill" or "University"). The Standard is applicable to all animals, except those for which an exception has been submitted to and approved by the Institutional Animal Care and Use Committee (IACUC). The UNC-Chapel Hill IACUC expects that anyone involved in animal work at the University will comply with this Standard. Requests for exceptions to this Standard must be reviewed and approved by the IACUC.

Standard

Mice:

All mouse cages must be provided with some type of environmental enrichment. This can include DCM standardized enrichment options, nesting material, seeds, etc. DCM will utilize multiple enrichment items in each cage whenever possible. Should an alternative enrichment item be preferred instead of DCM standardized environmental enrichment, please coordinate details with DCM facility managers. No amendment or exception is required for this option. To opt out of the second enrichment item, please contact your DCM facility manager directly, as an Exception is not required unless opting out of ALL enrichment items for the cage.

All mouse breeding cages must be provided with some form of nesting material, which may consist of nestlets, crinkle paper, or other suitable substitute readily available to DCM. All nude mice must be provided with nesting material (other than a nestlet) or a red hut, platform, or shelter.

Other Animals

Each animal enclosure must be provided with at least one enrichment item (or a veterinary approved alternative):

Species-specific Environmental Enhancement Plans, created and approved by the UNC-Chapel Hill Environmental Enrichment Committee, should be referenced when implementing new enrichment methods for species other than mice. Contact your DCM Facility Manager or Veterinary Services to obtain a copy.

Below are a few examples of some common methods referenced in these plans, but are not intended to be a complete description of the enrichment methods utilized at UNC-Chapel Hill:

• brown crinkle paper,
• puzzles,
• food treats,
• hide boxes,
• chew toys,
• perches,
• balls.

All will be provided with enrichment according to their specific needs, which may include group housing.

Every attempt will be made to choose items that enrich the animal’s environment and are durable, cage-dedicated, sanitizable, and safe. The above items have been used at many other institutions and have been considered beneficial. If necessary, pilot studies will be conducted before broadly introducing new enrichment items.

Exceptions

Requests for exceptions to this Standard must be reviewed and approved by the IACUC.

Instances may arise when social grouping or enrichment items may be inappropriate for the scientific goals of the study or the health of the animals. If investigators provide justification that providing cage enrichment would have a negative impact on the study or to their animals, an exception to the Standard may be granted by the IACUC on a case-by-case basis.

Exceptions to the Enrichment Standard must first be approved by the IACUC. Meetings are held monthly. Cages exempt from the standard must be clearly identified with a capital red letter “E” in the upper right corner of the DCM barcoded cage card. In a reverse light cycle room, this capital “E” should be in black or blue ink.

To request an exception, complete addendum 8.0 of the Animal Care Application (ACAP), Exception Request Form, and submit it electronically to the IACUC as part of a full application or as an amendment to an already approved application. Describe the scientific rationale for withholding environmental enrichment so the IACUC can adequately consider your request. Once approved, the lab should place a copy of the most updated version in the allocated binder within the animal holding room.

Related Requirements

University Policies, Standards, and Procedures

For more detailed guidance, please refer to the University Policy on the Care and Use of Vertebrate Animals for Research, Training, and Teaching Purposes

Contact Information

Approved by: UNC IACUC

Important Dates

• Effective Date and title of Approver: 1/5/05; UNC IACUC
• Revision and Review Dates: July 10, 2009, September 10, 2010, October 12, 2012, February 2015, July 2016, April, 2018: added: DCM will utilize multiple enrichment items in each cage whenever possible. To opt out of the second enrichment item, please contact your DCM facility manager directly, as an Exception is not required unless opting out of ALL enrichment items for the cage; February 16, 2023