These studies were designed to determine the feasibility of utilizing a pelleted
cellulose-based bedding material for our
institution’s rodent population. Our studies show that cellulose bedding is clean
and absorptive. The 3-to-10-fold decrease
in spot changes not only decreases material costs, but also decreases costs related
to cage processing and personnel time
associated with off-cycle cage changes.
Additionally, it minimizes animal stress
associated with frequent handling.
We found no significant changes in
breeding productivity or pup survival
when animals were housed on pelleted
cellulose bedding. In fact, we believe that
our reproduction may very well increase
after animals acclimate to the new
material, due to the decreased animal
handling and decrease of exogenous phy-toestrogens within the bedding material.
Flood-testing of the varying bedding
types confirmed the increased absorbability of cellulose bedding, thus confirming
one of the many advantages of switching
to this type of bedding.
Preference testing was not performed
with this project, but caregiver observations indicated animals were nesting
more frequently and interacting with the
bedding more naturally. Additionally,
both formulations of cellulose bedding
are smoother and softer to the touch
than corn-cob, presumably making
them a more comfortable bedding for
rodents. There were no mechanical
issues detected with bedding dispensers
or disposal systems related to either
cellulose bedding, so a transition to this
bedding could be made without the cost
of replacing expensive equipment.
In the future, we would like to further
quantify the effect of bedding changes on
breeding productivity and perform a complete cost-benefit analysis to determine
the savings associated with the decrease
in employee workload and cage processing (chemicals, machine wear-and-tear,
etc.) as compared to the overall cost of
As a change is made for the breeding
colony to a cellulose based bedding, we
will be able to further quantify these
factors, and based on the results may
consider a full facility transition to a
cellulose based bedding for the overall
welfare of the animals and the decrease
in associated costs.
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reproductive productivity or pup
Our trials were performed in rooms
housing our department-managed breeding colony which allowed us to analyze
the total number of litters born, as well
as the number of deceased pups identified during the trial. These values were
tallied daily during routine health monitoring activities and statistically analyzed
at the end of the study using t-tests.
No significant differences were noted
in the number of new litters born or
number of deceased pups for either trial
(p value of >0.05). We did not intend to
make a direct comparison between the
two trials, but instead used the repeated
trial with a new formulation of cellulose
bedding to confirm our previous findings.
Interestingly, the breeding levels
observed with the two trials seems
to indicate a trend towards increased
breeding values (as detected by total litters born and number of deceased pups
found). This trend, however requires
ANALYSIS OF A CAGES ABILITY TO
ABSORB WATER IN THE EVENT OF A
In addition to cage cleanliness and reproductive values, we felt it necessary to
evaluate the ability of a bedding material
to provide a safe environment for animals
in the event of cage floods. Flooded cages
are an important cause of morbidity and
mortality in mouse colonies, especially
in neonates or genotypes unable to cope
with environmental stress.
To evaluate the ability of a cage of
bedding to absorb water, a standard sized
water bottle (200 mL) was dumped into
cage of bedding and allowed to absorb
for a total of five minutes to simulate
a flooded cage. After five minutes had
passed, remaining water was strained
from bedding and poured into graduated cylinder to determine the volume of
water that was not absorbed.
Both types of cellulose bedding were
better than corn-cob regarding water
absorption, as indicated by the decrease
in free-water detected within the bedding
after a five-minute absorption period.