title: Effects of cage size and enrichment on reproductive performance and behavior in C57BL/6Tac mice.
abstract: The authors examined the effects of cage size and enrichment on mouse breeding performance and behavior. Breeding trios of C57BL/6Tac mice were housed in cages of two different sizes ('standard' and 'large' cages with 82 in(2) and 124 in(2) floor space, respectively). Half of the cages of each size contained four enrichment items (Nestlet, plastic tunnel, nylon rings and running wheel), whereas the remaining cages had no enrichment. The authors measured the following reproductive parameters: litter size, number of pups that survived to weaning age, average pup weights at 21 d after birth and number of days between births of litters. A subset of weaned male and female pups from each cage size and enrichment condition completed a suite of behavioral tests. Pups raised in large cages weighed less than those raised in standard cages. Enrichment and cage size had certain behavioral effects, which were dependent on gender and behavioral measure. Male pups born in enriched cages showed more anxiety-like behavior and less exploration than did males born in non-enriched cages. Though being raised in enriched or large cages did not clearly improve pups' performance in behavioral tests, enrichment (regardless of cage size) did significantly benefit reproductive performance; pups from non-enriched cages weighed less than pups from enriched cages, and fewer survived to weaning age.
authors.affiliation: Division of Laboratory Animal Medicine, Department of Pathology and Laboratory Medicine, 1100 Bioinformatics, CB 7115. julia_whitaker@med.unc.edu
authors.forename: Julia
authors.initials: J
authors.lastname: Whitaker
authors.forename: Sheryl S
authors.initials: SS
authors.lastname: Moy
authors.forename: Virginia
authors.initials: V
authors.lastname: Godfrey
authors.forename: Judith
authors.initials: J
authors.lastname: Nielsen
authors.forename: Dwight
authors.initials: D
authors.lastname: Bellinger
authors.forename: John
authors.initials: J
authors.lastname: Bradfield
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001007:Anxiety / Q000473:pathology; D001835:Body Weight; D005106:Exploratory Behavior / Q000502:physiology*; D005260:Female; D005298:Fertility / Q000502:physiology*; D006799:Housing, Animal; D008098:Litter Size / Q000502:physiology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D045442:Rotarod Performance Test; D012726:Sexual Behavior, Animal / Q000502:physiology*