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Effect of Cage Space on Behavior and Reproduction in Crl:CD(SD) and BN/Crl Laboratory Rats

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 cm2, 758 cm2, 903 cm2, or 1355 cm2) 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.

Behaviour of Rats in their Home Cages: Daytime
Variations and Effects of Routine Husbandry
Procedures Analysed by Time Sampling

The behaviour of laboratory rats in their home cages was observed on both the mornings and the afternoons of days when cages were cleaned and compared to days when cages were not cleaned. Two different time sampling methods, ‘instantaneous sampling’ and ‘one/zero sampling’, were used and compared. In general the rats were more active in the mornings than in the afternoons. Activity, particularly locomotion and that associated with manipulation of the bedding was increased during both the mornings and the afternoons of cleaning days. Defaecation also increased on cleaning days whereas sitting decreased.

Rats Free Each Other from Cages

    Rats, often anthropomorphized as greedy and selfish, may not be the callous, cartoon villains they are sometimes made out to be. A paper published today in Science demonstrates that the rodents will liberate trapped cage-mates — even when they have nothing to gain1.

    There is a growing body of research showing that animals respond to the emotions of others. But it wasn’t certain whether rats could suppress their own distress in order to aid another rat.

    Automated Recording of Home Cage Activity and Temperature of Individual Rats Housed in Social Groups: The Rodent Big Brother Project

          Measuring the activity and temperature of rats is commonly required in biomedical research. Conventional approaches necessitate single housing, which affects their behavior and wellbeing. We have used a subcutaneous radiofrequency identification (RFID) transponder to measure ambulatory activity and temperature of individual rats when group-housed in conventional, rack-mounted home cages. The transponder location and temperature is detected by a matrix of antennae in a baseplate under the cage. An infrared high-definition camera acquires side-view video of the cage and also enables automated detection of vertical activity. Validation studies showed that baseplate-derived ambulatory activity correlated well with manual tracking and with side-view whole-cage video pixel movement.

          Cage Size Preference in Rats in the Laboratory

                he size of an enclosure is an integral part of how well it accommodates a nonhumananimal’s welfare; however, most enrichment studies concentrate on modifying thearea inside the enclosure rather than enlarging it. It has been suggested that rats havelittle need for more cage space, but there is no empirical evidence about rats’ need forspace. This experiment provides preliminary evidence for the preferences of 5 maleand 5 female albino rats using T-maze choices followed by 5 min dwelling times. Therats showed a moderate but significant preference for the larger of 2 cages (540 cm2vs. 1,620 cm2; binomialz,p< .05).
                (PDF) Cage Size Preference in Rats in the Laboratory. Available from: https://www.researchgate.net/publication/10766704_Cage_Size_Preference_in_Rats_in_the_Laboratory [accessed Jun 22 2020].

                Social, Maternal and Aggressive Behaviors in Rodents

                      Many standard behavioral tests exist for the study of interactive behavior in mice and rats. In order to choose the most appropriate test for a research study it is important to understand something about the range of rodent social behaviors and what, specifically, behavioral tests are attempting to measure.

                      Rats and mice used in research are considered social species, meaning, in general, they prefer some form of group living. Species that live together must interact and so have evolved various behaviors that allow and facilitate group living.

                      The Importance of Burrowing, Climbing and Standing Upright for Laboratory Rats

                            Standard laboratory cages prevent rats (Rattus norvegicus) from performing many behaviours that they perform in the wild, but little is known about how this may affect their welfare. The aims of this study were (i) to record the propensity to burrow, climb and stand upright in 3-, 8- and 13-month old laboratory rats housed in semi-naturalistic environments and (ii) to compare the frequency of lateral stretching in semi-naturalistic versus standard-housed rats; we predicted standard-housed rats would perform more lateral stretches to compensate for the inability to stretch upright. Rats’ propensity to burrow remained constant as they aged (approx. 30 bouts per day totalling 20–30 min), suggesting burrowing is important to rats.

                            Lab Rats Play Hide-and-Seek for the Fun of it, New Study Shows

                                  Every child knows that a proper game of hide-and-seek must follow a strict set of rules. Players can’t switch from being the “seeker” to the “hider” midway through the game, for example, and hiders have to stay put until they’re found. Now, scientists have discovered that lab rats can rapidly learn the rules to hide-and-seek and, so far as they can tell, love playing the game with people.