Elevating the welfare of mouse dams: A pilot study on elevated tunnels for breeding mice (2024)

Ratuski, A. S., Makowska, I. J., Weary, D. M.,

Abstract

Mouse dams and their pups may benefit from more gradual weaning, but this is not possible in standard laboratory cages because dams cannot physically separate from their pups. Allowing mouse dams to control nursing may improve their welfare and encourage pups to start eating solid food earlier, potentially reducing the stress of abrupt weaning. In this pilot study, we housed mouse dams and their pups with or without an elevated tunnel to see if dams used tunnels more as pups approached weaning, and whether tunnel access affected maternal behavior, dam anxiety, or pup weights. Tunnel use did not increase as pups got older, and there were no treatment differences in the outcomes measured. However, the lack of positive effects might be due to: (1) individually ventilated cages with air inlets and outlets at the lid level, making the tunnels drafty and colder compared to the nest, and (2) the tunnels hanging low enough that pups were able to jump into them early on.