Witt, S. L., Plews, C. A., Ruppert, G. et al. 2011. Nylon cylinder: Safe and cost-effective chewable rat enrichment. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 782 (Abstract #P174).

Offering enrichment to stimulate chewing behavior in rats has been found to promote psychologic and physiologic wellbeing. While there are many commercially produced nylon products available for use as chewable enrichment, these items are costly, especially with current economic constraints. FDA-certified 8-ft lengths of 1-in. thick nylon cylinders cut into 3-in. pieces were identified as a possible cost effective alternative. To determine safety and efficacy, a 4-wk study was conducted on male and female CD rats. Six animals per sex received no chewing enrichment (control group), 6 animals per sex received nylon chew toys (positive control group), and 6 animals per sex received the 3-in. nylon cylinder pieces (test article group). Clinical observation, food consumption, body weight, clinical chemistry, hematology, and microscopic observation data were collected from all animals. Additionally, the enrichment items themselves were weighed to measure usage. No test article-related effects or differences in overall usage were noted. The nylon cylinder proved to be an acceptable alternative to the more costly nylon products. We have also demonstrated that chewable nylon enrichment devices can be safely used on drug safety studies without adversely affecting commonly assessed endpoints.