Paula, A. A., Goyeneche, L., Crispo, M. 2011. Refining housing and husbandry techniques in transgenic mice through environmental enrichment. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 777 (Abstract #P148).

Dynamic changes in housing and husbandry techniques based on the concept of 3Rs should be included as routine practice in breeding and experimental animal facilities tending to improve animal welfare. Immunosupressed mice are susceptible to diseases and have special requirements for husbandry and maintenance. In this case we tried to improve welfare and optimize the reproduction of a transgenic colony through environmental enrichment. The effects were evaluated by progeny production and frequency of species-specific conduct as behavioral indicators. The design consisted on the combination and alternation of materials for social and physical enrichment (environment complexity, nesting material, sensory and nutritional enhancement) every week within the cage changing in routine husbandry to the experimental group (n = 13) and no enrichment to the control group (n = 13), during 3 mo. Number of pups born alive, pups per female and survival rate at third week of age were evaluated and analyzed by χ2 tests. Results showed that 58.6 % of pups born alive belonged to the experimental group (P < 0.05), with a higher number of pups per female (9.1 compared with 6.4) and a higher survival rate than the control group (94% compared with 70%; P < 0.05). An initial and final ethogram showed an increase in frequency of exploratory behavior in the experimental group. With this experience, a refinement was made through environmental enrichment implementation. Fewer breeders could be used based on the increased number of pups and survival rate, and an improvement in animal wellbeing maximizing species-specific behavior could be achieved. Moreover, collecting data and performing new refinement protocols are important for the establishment of new guidelines on housing and husbandry techniques based on a responsible and rational use of laboratory animals.