title: Effect of Enrichment Devices on Aggression in Manipulated Nude Mice.
abstract: Agonistic behavior in group-housed male mice is a recurring problem in many animal research facilities. Common management procedures, such as the removal of aggressors, are moderately successful but often fail, owing to recurrence of aggressive behavior among cagemates. Studies have incorporated enrichment devices to attenuate aggression, but such devices have had mixed results. However, these studies did not include research manipulations when assessing the benefits of various enrichment devices. We obtained 100 male athymic nude mice and studied the efficacy of various enrichment devices, including cotton squares, paper rolls, shredded paper, nylon bones, and a mouse house and wheel combination in the reduction of fighting during an ongoing study that involved randomization followed by prostate and intratibial injections. Groups were evaluated according to a numerical grading system for wound assessment. Examination of the data revealed that the enrichment devices had no effect on the presence of wounds, thus none of the devices tested affected fighting in nude mice. However, when mice began experimental use, fight wounds increased significantly at cage change and after randomization, reflecting a disruption of existing social hierarchies. Therefore, in the context of an actual research study that involves common manipulations, the specific enrichment device had less effect on aggression in male nude mice than did the destruction and reconstruction of social structures within each group.
authors.affiliation: Department of Veterinary Medicine and Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA. crlockworth@mdanderson.org.
authors.forename: Cynthia R
authors.initials: CR
authors.lastname: Lockworth
authors.affiliation: Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Sun-Jin
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA; Department of Biostatistics, Kansas State University, Manhattan, Kansas, USA.
authors.forename: Shana L
authors.initials: SL
authors.lastname: Palla
authors.affiliation: Department of Veterinary Medicine and Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Craig
mesh_terms: D000374:Aggression; D000827:Animal Welfare; D000818:Animals; D001512:Bedding and Linens / Q000662:veterinary; D006799:Housing, Animal; D008297:Male; D051379:Mice; D008819:Mice, Nude / Q000502:physiology*; D011897:Random Allocation