Multidimensional cost-benefit analysis to guide evidence-based environmental enrichment: providing bedding and foraging substrate to pen-housed monkeys

Abstract

Refinement of animal care and housing is an important shared goal-and challenge-of the team of research, veterinary, and animal care personnel charged with ensuring the wellbeing of laboratory animals. This study addresses 2 issues central to decision-making and implementation of environmental enhancement: methods for useful and comprehensive cost analysis and evaluation of engineering, husbandry, and facilities considerations. The study was undertaken to analyze the feasibility and cost of providing wood shavings as a floor cover for pen-housed monkeys. The beneficial effects of bedding for the welfare of laboratory-housed animals have long been validated. Our study illustrates a workable team-based procedure for comprehensive cost analysis of an important environmental enhancement and demonstrates that the animal welfare benefit is accompanied by decreased husbandry costs. An engineering solution to the potential challenge that wood shavings pose in terms of clogging water pipes was successful. Another successful outcome was the reduction in water (estimated at 192,000 gal annually) and chemicals used to clean housing areas. Emphasis on rigorous evaluation and objective measures of cost and benefit, as well as inclusion of the many factors and teams involved in animal research, holds strong potential for building a better foundation from which to contribute effective changes and improvements in laboratory animal welfare. Taken together, the findings of this study demonstrate that team-based, integrative, and scientific evaluation of environmental enhancement is an effective approach to guide selection of strategies with maximal potential for improving animal welfare.

Figure 1.

(A) Device used to cover the drains in each animal pen. The device was constructed from high-density polyethylene and (B) attached to the gate of the drain with a spring loaded-T-hook mechanism made of stainless steel bar stock. (C) The drain cover fit flush against the drain and (D) prevented shavings from entering the drain.

Figure 2.

Adolescent male bonnet macaque exploring wood shavings on the floor of his indoor pen housing environment.

Figure 3.

Overall study design and husbandry procedures.