Oteham, C. P. 2010. Effects of specific environmental enrichment contributing to litter size and attrition rate of TRP1/TGfβ transgenic mice in a breeding colony. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 698 (Abstract #P51).

In previous studies of environmental enrichment of mice it has been determined that certain types of mice are affected by manipulation of their living environment. Some have effects on cognitive memory and some affect the developmental nurturing on second and third generational animals. It has been determined that environmental enrichments impact these areas, but it has not been shown if they have an effect on litter size and attrition rate. Four experimental harem groups were set up with control harem groups (with no enrichment items) to determine which environmental enrichment items were used and if this was a determining factor in the litter size of each group. All of the harem animals were of the same age and strain type. The animals were observed 2 times per day and record of all activity was noted. This observation lasted 100 d to ensure the mating, births, and weaning of the pups were documented. In the evaluation of the harem caging with enrichment items it was observed that the activity level increased. Offspring were noted to have more attention by all parental mice in the enriched caging versus the control caging, but that certain enrichment items present in the cage tended to determine how the pups were nurtured and shared. General housekeeping was monitored as well as grooming habits to pups and adults sharing caging. Litter sizes and pups surviving until weaned from the enriched caging exhibited a slight increase over the control caging. It was observed that the enriched caging was up in production and survival to weaning by nearly 4% over control caging and that paper enrichment caging was higher than other enrichment caging items. These results would suggest that providing specific enrichment encourages more natural behavior and less stress in this particular strain influencing litter size and attrition rate.