Effects of environmental enrichment on outcomes of in vitro fertilization-embryo transfer in ICR mice.

The effects of environmental enrichment (EE) on mother mice and their pups following in vitro fertilization-embryo transfer (IVF-ET) were evaluated. Mother mice were maintained with or without EE, which consisted of a house and three types of nest materials, immediately after embryo transfer into the fallopian tube. EE did not appear to have a beneficial effect on the surgical wounds of the mother mice. Although EE did not significantly affect litter sizes, it tends to increase the weaning rate. Additionally, EE increased 11% and 6% body weight gain in the male and female pups, respectively. EE tended to decrease fecal cortisol during the lactating period. Collectively, EE seems to improve the lactating environment of mother mice, thereby enhancing IVF-ET productivity.