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Heat or insulation: behavioral titration of mouse preference for warmth or access to a nest.

Gaskill BN, Gordon CJ, Pajor EA, Lucas JR, Davis JK, Garner JP - PLoS ONE (2012)

Bottom Line: This increased thermal stress has the potential to alter scientific outcomes.Nesting material should allow for improved behavioral thermoregulation and thus alleviate this thermal stress.In addition, temperature pairings altered the difference in nest scores with the smallest difference between locations at 26°C and 29°C.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal Science, Purdue University, West Lafayette, Indiana, United States of America. brianna.gaskill@crl.com

ABSTRACT
In laboratories, mice are housed at 20-24°C, which is below their lower critical temperature (≈30°C). This increased thermal stress has the potential to alter scientific outcomes. Nesting material should allow for improved behavioral thermoregulation and thus alleviate this thermal stress. Nesting behavior should change with temperature and material, and the choice between nesting or thermotaxis (movement in response to temperature) should also depend on the balance of these factors, such that mice titrate nesting material against temperature. Naïve CD-1, BALB/c, and C57BL/6 mice (36 male and 36 female/strain in groups of 3) were housed in a set of 2 connected cages, each maintained at a different temperature using a water bath. One cage in each set was 20°C (Nesting cage; NC) while the other was one of 6 temperatures (Temperature cage; TC: 20, 23, 26, 29, 32, or 35°C). The NC contained one of 6 nesting provisions (0, 2, 4, 6, 8, or 10g), changed daily. Food intake and nest scores were measured in both cages. As the difference in temperature between paired cages increased, feed consumption in NC increased. Nesting provision altered differences in nest scores between the 2 paired temperatures. Nest scores in NC increased with increasing provision. In addition, temperature pairings altered the difference in nest scores with the smallest difference between locations at 26°C and 29°C. Mice transferred material from NC to TC but the likelihood of transfer decreased with increasing provision. Overall, mice of different strains and sexes prefer temperatures between 26-29°C and the shift from thermotaxis to nest building is seen between 6 and 10 g of material. Our results suggest that under normal laboratory temperatures, mice should be provided with no less than 6 grams of nesting material, but up to 10 grams may be needed to alleviate thermal distress under typical temperatures.

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The mean difference in nest score values between the nesting cage and the temperature cage.Nest scores partitioned by occurrences of nesting material carryover by (a) cage sets and (b) amount of material provided. A negative value indicates a better nest built in the temperature cage and a positive value indicates a better nest in the nesting cage. LSM and SE are plotted and significant t-tests (value different from zero; α corrected for the number of comparisons) are indicated by asterisks. A diagonal line indicates a significant linear trend and a curved line indicates a significant quadratic trend.
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pone-0032799-g002: The mean difference in nest score values between the nesting cage and the temperature cage.Nest scores partitioned by occurrences of nesting material carryover by (a) cage sets and (b) amount of material provided. A negative value indicates a better nest built in the temperature cage and a positive value indicates a better nest in the nesting cage. LSM and SE are plotted and significant t-tests (value different from zero; α corrected for the number of comparisons) are indicated by asterisks. A diagonal line indicates a significant linear trend and a curved line indicates a significant quadratic trend.

Mentions: Nest quality was also affected by temperature (GLM: F5,308 = 12.6; P<0.001), but nest scores changed when the mice transferred nesting material (GLM: F5,308 = 6.6; P<0.001; Figure 2a). Mice that did not transfer the material show a transitive decrease in nest score with temperature (Linear Contrast: F1,308 = 7.21; P = 0.007), with the highest nest score found in the 20–20°C temperature-sets. All nest scores were significantly higher in NC at all temperatures (t α/12; P<0.05). When material is transferred, a significant quadratic trend was found (Quadratic Contrast: F1,308 = 32.1; P<0.001). Here nest scores were significantly higher in TC at 23 and 26°C and NC at 35°C (t α/12;P<0.05). All other temperatures showed no significant differences in nest scores between the two cages.


Heat or insulation: behavioral titration of mouse preference for warmth or access to a nest.

Gaskill BN, Gordon CJ, Pajor EA, Lucas JR, Davis JK, Garner JP - PLoS ONE (2012)

The mean difference in nest score values between the nesting cage and the temperature cage.Nest scores partitioned by occurrences of nesting material carryover by (a) cage sets and (b) amount of material provided. A negative value indicates a better nest built in the temperature cage and a positive value indicates a better nest in the nesting cage. LSM and SE are plotted and significant t-tests (value different from zero; α corrected for the number of comparisons) are indicated by asterisks. A diagonal line indicates a significant linear trend and a curved line indicates a significant quadratic trend.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3316552&req=5

pone-0032799-g002: The mean difference in nest score values between the nesting cage and the temperature cage.Nest scores partitioned by occurrences of nesting material carryover by (a) cage sets and (b) amount of material provided. A negative value indicates a better nest built in the temperature cage and a positive value indicates a better nest in the nesting cage. LSM and SE are plotted and significant t-tests (value different from zero; α corrected for the number of comparisons) are indicated by asterisks. A diagonal line indicates a significant linear trend and a curved line indicates a significant quadratic trend.
Mentions: Nest quality was also affected by temperature (GLM: F5,308 = 12.6; P<0.001), but nest scores changed when the mice transferred nesting material (GLM: F5,308 = 6.6; P<0.001; Figure 2a). Mice that did not transfer the material show a transitive decrease in nest score with temperature (Linear Contrast: F1,308 = 7.21; P = 0.007), with the highest nest score found in the 20–20°C temperature-sets. All nest scores were significantly higher in NC at all temperatures (t α/12; P<0.05). When material is transferred, a significant quadratic trend was found (Quadratic Contrast: F1,308 = 32.1; P<0.001). Here nest scores were significantly higher in TC at 23 and 26°C and NC at 35°C (t α/12;P<0.05). All other temperatures showed no significant differences in nest scores between the two cages.

Bottom Line: This increased thermal stress has the potential to alter scientific outcomes.Nesting material should allow for improved behavioral thermoregulation and thus alleviate this thermal stress.In addition, temperature pairings altered the difference in nest scores with the smallest difference between locations at 26°C and 29°C.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal Science, Purdue University, West Lafayette, Indiana, United States of America. brianna.gaskill@crl.com

ABSTRACT
In laboratories, mice are housed at 20-24°C, which is below their lower critical temperature (≈30°C). This increased thermal stress has the potential to alter scientific outcomes. Nesting material should allow for improved behavioral thermoregulation and thus alleviate this thermal stress. Nesting behavior should change with temperature and material, and the choice between nesting or thermotaxis (movement in response to temperature) should also depend on the balance of these factors, such that mice titrate nesting material against temperature. Naïve CD-1, BALB/c, and C57BL/6 mice (36 male and 36 female/strain in groups of 3) were housed in a set of 2 connected cages, each maintained at a different temperature using a water bath. One cage in each set was 20°C (Nesting cage; NC) while the other was one of 6 temperatures (Temperature cage; TC: 20, 23, 26, 29, 32, or 35°C). The NC contained one of 6 nesting provisions (0, 2, 4, 6, 8, or 10g), changed daily. Food intake and nest scores were measured in both cages. As the difference in temperature between paired cages increased, feed consumption in NC increased. Nesting provision altered differences in nest scores between the 2 paired temperatures. Nest scores in NC increased with increasing provision. In addition, temperature pairings altered the difference in nest scores with the smallest difference between locations at 26°C and 29°C. Mice transferred material from NC to TC but the likelihood of transfer decreased with increasing provision. Overall, mice of different strains and sexes prefer temperatures between 26-29°C and the shift from thermotaxis to nest building is seen between 6 and 10 g of material. Our results suggest that under normal laboratory temperatures, mice should be provided with no less than 6 grams of nesting material, but up to 10 grams may be needed to alleviate thermal distress under typical temperatures.

Show MeSH
Related in: MedlinePlus