Pine vs. Paper Test Results

Below are excerpts from a technical evaluation done on pet beddings published by the American Association for Laboratory Animal Science (AALAS). Download PDF of study results.

INTRODUCTION

Evaluation of Cage Micro-Environment of Mice Housed on Various Types of Bedding Materials
ELLEN SMITH, JASON D. STOCKWELL, PHD,† ISABELLE SCHWEITZER, MS, STEPHEN H. LANGLEY, BS, AND ABIGAIL L. SMITH, MPH, PHD*
"
A variety of environmental factors can affect the outcomes of studies using laboratory rodents. One such factor is bedding. Several new bedding materials and processing methods have been introduced to the market in recent years, but there are few reports of their performance. In the studies reported here, we have assessed the cage micro-environment (in-cage ammonia levels, temperature, and humidity) of mice housed on various kinds of bedding and their combinations. We also compared results for bedding supplied as Nestpaks versus loose bedding. We studied C57BL/6J mice (commonly used) and NOD/LtJ mice (heavy soilers) that were maintained, except in one study, in static duplex cages. In general, we observed little effect of bedding type on in-cage temperature or humidity; however, there was considerable variation in ammonia concentrations."

RESULTS

"The 3-week experiment with male NOD/LtJ mice. Differences in temperature were not systematically related to bedding material and varied only 1.1ºC (24.0ºC to 25.1ºC) between the lowest and highest averages for the three seasons. Least-squares means (± standard error) of RH for all control cages (with bedding but no mice) were significantly lower (39.5% ± 0.1%) than those for cages housing mice (60.8% ± 2.4%;). The mean RH in cages housing mice on the Bed-O'cobs plus ALPHA-dri (56.6% ± 0.7%) was significantly lower than that for all other tested bedding material except CareFRESH Ultra (59.1% ± 2.0%)."

"The mean ammonia concentrations in static cages housing mice on CareFRESH Ultra bedding were significantly higher than the means for all the other bedding treatments (Table 2). Unexpectedly, the ammonia concentrations in cages housing mice on CareFRESH Ultra bedding were very high at 2 weeks (65.4 to 390.2 ppm), so we removed that group from the study. Mean ammonia levels in cages with pine shavings, Cell-Sorb Plus, a mixture of pine shavings and ALPHA-dri, and Bed-O'cobs did not differ significantly from each other but were significantly different from other bedding types (Table 2)."


(download PDF to read complete study results)