title: Effect of Cage Space on Behavior and Reproduction in Crl:CD(SD) and BN/Crl Laboratory Rats.
abstract: The 2011 Guide for the Care and Use of Laboratory Animals contains recommendations regarding the amount of cage space for mothers with litters. Literature on cage-space use in breeding rats is sparse. We hypothesized that, if present, differences in behavior and reproduction would be detected between the smallest and largest cages tested. BN/Crl and Crl:CD(SD) rats were assigned to a cage treatment (580 cm(2), 758 cm(2), 903 cm(2), or 1355 cm(2)) and breeding configuration (single: male removed after birth of pups; pair: 1 male, 1 female) in a factorial design for 12 wk. All cages received 20 to 25 g of nesting material, and nests were scored weekly. Pups were weaned, sexed, and weighed between postnatal days 18 and 26. Adult behavior and location in the cage were videorecorded by scan-sampling on the litter's postnatal days 0 through 8 and 14 through 21. Press posture in adults and play behavior in pups were recorded according to a 1-0 sampling method. Differences in reproductive parameters were limited to expected differences related to rat genetic background and weaning weight in pups, which was lowest in the pair-bred CD rats in the smallest cages. Press posture in adults in the smaller cages increased as the pups became mobile. Pair-housed outbred rats in the smallest commercially available cage we tested showed behavioral changes and a lower pup weaning weight. Both laboratory animal scientists and caging manufacturers should address the challenge of providing more biologically relevant cage complexity rather than merely increasing floor space.
authors.affiliation: Department of Comparative Pathobiology, Purdue University, West Lafayette, Indiana, USA; Charles River, Wilmington, Massachusetts, USA. bgaskill@purdue.edu.
authors.forename: Brianna N
authors.initials: BN
authors.lastname: Gaskill
authors.affiliation: Office of Animal Resources, Faculty of Arts and Sciences, Harvard University, Cambridge, Massachusetts, USA; Charles River, Wilmington, Massachusetts, USA.
authors.forename: Kathleen R
authors.initials: KR
authors.lastname: Pritchett-Corning
mesh_terms: D000818:Animals; D000830:Animals, Laboratory; D001522:Behavior, Animal; D001835:Body Weight; D005260:Female; D006799:Housing, Animal; D008297:Male; D008425:Maternal Behavior; D051381:Rats / Q000145:classification / Q000235:genetics / Q000502:physiology*; D011914:Rats, Inbred BN; D012098:Reproduction; D013045:Species Specificity; D014886:Weaning