Effect of prenatal and postnatal environmental enrichment on laboratory rats' welfare

Document Type : Original Article


1 Department of Hygiene, Management and Zoonoses, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt

2 Department of Animal Wealth, Faculty of Veterinary Medicine, Menia University, Egypt


This work was designed to investigate effects of environmental enrichment during
gestation on behaviour, physiology and brain histology of enriched and non-enriched
offspring rats. A total of 30 female wistar rats were randomly divided into two groups;
control and enriched groups. Offspring from prenatally enriched group were divided
after weaning into two groups; one raised under standard condition (enriched group)
and the other raised under enriched condition after weaning (E+EC group) from the
day 23 to the day 35 postnatal. Observing neonates' behaviour, on the day 36
postnatal, rats subjected to behavioural tests. On the day 42 postnatal, blood samples
were collected and brain samples were obtained for histopathology. Behavioural tests
revealed significant (P<0.05) increased time spent in open arm, open arm entries and
time in center in E+EC group and unprotected stretch attend posture (USAP) were
significantly (P<0.01) increased in E+EC group. Freezing time in open field test was
significantly (P<0.01) decreased in the enriched group, while grooming frequency was
significantly (P<0.05) increased in prenatally and post weaning enriched rats group < br />(E+EC). The corticosterone level was significantly (P<0.05) decreased in prenatally and
post weaning enriched rats group (E+EC). The mean of tertiary processes of
cytoplasmic processes in cross section of hippocampal region were significantly
(P<0.05) increased in prenatally and post weaning enriched rats group (E+EC) group.
In conclusion, providing experimental laboratory rats with physical enrichment tools
in prenatal and postnatal life can improve their behavioural and physiological status
reflecting on their welfare.


Main Subjects