Strickland, B. 2023. Comparison of three environmentally friendly enrichments in single-housed Sprague Dawley rats. Laboratory Animal Science Professional 11(5) (September/October), 56-57.

Numerous studies have shown the negative side effects the lack of enrichment has on the overall health of animals in research. This lack in data may lead to unnecessary risks for welfare issues, like the single housed lab rats that are already impacted by not being able to socialize per their nature. The rationale for making novel and different enrichment is to better our animals’ lives and to improve research. The goal of this study was to create low-cost enrichment, from material that was readily available to the facility and evaluate use in single housed rats. We hypothesized that rats would prefer cardboard toys compared to paper toys, and that the rats prefer the Timothy hay over recycled shredded paper. Fifty-one singly housed rats were given one of three recycled toys for 4 days. The usage of the toy was monitored daily with measuring how much of the toy was utilized, nest scoring, and observation of any behaviors, such as rearing, ignoring, or happily chewing on enrichment. Any parts of the toy that remained after the 4-day period were removed from cages. A two-day wash out was performed before the next toy was given. Three disposable toys were designed with recycled materials of cardboard tube, paper, and cardboard box. Each toy can hold a secondary enrichment method of shredded paper or Timothy hay in the middle of each toy (total of 6 different toys). We demonstrate that rats were more willing to use cardboard toys compared to paper toys and that rats preferred toys stuffed with hay over those stuffed with shredded paper. Hay can successfully be used for enrichment for rats.