Effect of Foraging Crumbles on Aggression in Mice

Environmental enrichments are used to simulate a more natural environment for laboratory animals and ideally improve their welfare. This improvement includes decreasing inter-animal aggression.

This study investigates whether Bioserv’s foraging crumbles decrease or increase aggression in male laboratory mice populations.

Behavioral assays will also be run at the end of the experiment to determine the cognitive effects of both aggression and foraging crumbles on the animals.

Imagine hundreds of lives being directly in your hands. Make that, thousands – make that, millions. This is the life of an animal researcher. 8 breeder mice that you care for will produce around a hundred offspring over a couple of litters, and the findings from these offspring will then be replicated in thousands more animals to model diseases that millions of humans are affected by. From there, you can do the math on how many people are affected every time just two of these mice fight, an event that not only is harmful for the animals but also influences data validity.

This is where studies such as those on environmental enrichments come in. Studies such as these aim to find materials that will simulate more natural environments and prevent detrimental effects, such as violence, from occurring. Dr. Flinn’s laboratory in the Krasnow Animal Facility at George Mason University, for instance, uses Bioserv’s foraging crumbles in attempt to prevent aggression in their mice. These foraging crumbles are little bits of food that mice can dig around and search for instead of just getting in the form of nuggets in a basket. While mice still have the option of getting nuggets, they have a new available activity they can choose to engage with. Ideally, this will prevent boredom, and thus aggression, seen in the mice. Although, this has not yet been shown in studies, and studies on other enrichments so far have confounding results. Whereas some studies show a decrease in aggression from a given enrichment, the same enrichment is found to increase aggression in other studies!

What happens when this aggression isn’t prevented, though? How does this impact data validity? Mice must be isolated if they cause injuries to other mice. It is known that social isolation causes cognitive impairments in social species such as mice. For laboratories looking at cognitive performance as Dr. Flinn’s does, this can make a significant difference, especially when certain experimental groups are more prone to violence. So, will mice that are isolated perform worse on cognitive-behavioral assays? On the other hand, having more opportunities for stimulating activities improves cognitive performance. Will mice raised with crumbles perform better?

This experiment aims to clarify these questions as well as whether raising mice with foraging crumbles increases or decreases aggression in laboratory mice. With this study, we aim to inform Bioserv, as well as all laboratories conducting animal research, on whether foraging crumbles may be a viable treatment for aggression in mice.

I’d like to thank Dr. Flinn and Rachel Barkey for their continued mentorship in this pursuit, the IACUC Review Committee for their feedback that has helped to shape and refine this study, and last but certainly not least OSCAR for their support, both financially and through structured guidance for this project. I’d also like to thank and acknowledge all the sources from which I gathered the information for this video. Thank you.