title: Long-term effects of husbandry procedures on stress-related parameters in male mice of two strains.
abstract: In socially unstable groups of male laboratory mice, individuals may experience a chronic stress situation. Previous experiments have shown that the transfer of specific olfactory cues during cage cleaning, and the provision of nesting material decrease aggression and stress in group-housed male mice. In this study, the combined effect of these husbandry procedures were tested for their long-term effect on stress in groups of moderately aggressive (BALB/c) and severely aggressive (CD-1) male mice. The physiological and behavioural stress-related parameters used were body weight, food and water intake, spleen and thymus weight, adrenal tyrosine hydroxylase activity, urine corticosterone levels and behaviour in a cage emergence test. Long-term provision of nesting material and its transfer during cage cleaning was found to influence several stress-related physiological parameters. Mice housed in cages enriched with nesting material had lower urine corticosterone levels and heavier thymuses, and they consumed less food and water than standard-housed mice. Furthermore, marked differences were found between strains. CD-1 mice were less anxious in the cage emergence test, weighed more, ate and drank more, and had heavier thymuses but lighter spleens and lower corticosterone levels than BALB/c mice. We conclude that the long-term provision of nesting material, including the transfer of nesting material during cage cleaning, reduces stress and thereby enhances the welfare of laboratory mice.
authors.affiliation: Department of Laboratory Animal Science, Utrecht University, PO Box 80.166, 3508 TD Utrecht, The Netherlands. P.L.P.vanloo@vet.uu.nl
authors.forename: P L P
authors.initials: PL
authors.lastname: Van Loo
authors.forename: E
authors.initials: E
authors.lastname: Van der Meer
authors.forename: C L J J
authors.initials: CL
authors.lastname: Kruitwagen
authors.forename: J M
authors.initials: JM
authors.lastname: Koolhaas
authors.forename: L F M
authors.initials: LF
authors.lastname: Van Zutphen
authors.forename: V
authors.initials: V
authors.lastname: Baumans
mesh_terms: D000378:Agonistic Behavior / Q000502:physiology*; D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D003345:Corticosterone / Q000652:urine; D003404:Creatinine / Q000652:urine; D004326:Drinking / Q000502:physiology; D004435:Eating / Q000502:physiology / Q000523:psychology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C / Q000502:physiology / Q000523:psychology*; D008813:Mice, Inbred ICR / Q000502:physiology / Q000523:psychology*; D009929:Organ Size; D011897:Random Allocation; D012930:Social Dominance; D013154:Spleen / Q000502:physiology; D013315:Stress, Psychological / Q000209:etiology / Q000523:psychology*; D013950:Thymus Gland / Q000502:physiology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D003404:Creatinine; D014446:Tyrosine 3-Monooxygenase; D003345:Corticosterone