Hussin M, Siti Amrah S, Zakiah I, Hasnan J and FJR Paumgartten (2014). Evaluation on the reproductive performance and spontaneous malformations amongst SD rats in the Institute for Medical Research colony. Malaysian Journal of Veterinary Research 5(1): 53-63
This study was performed to investigate the reproductive performance and spontaneous malformations of female Sprague Dawley (SD) rats obtained from the Animal Resource Unit, Institute for Medical Research for their use in reproductive toxicity assessment. One hundred and thirty-five virgin female rats with a body weight ranging between 190 g and 210 g were randomly caged overnight with 60 fertile male rats in 1:1 basis. Vaginal smear was performed the next morning and the day of sperm positive was considered as gestational day (GD) 0. On GD21 caesarean hysterectomy was performed to examine the outcome of each pregnancy. The female fertility index (sperm positive) was 90.5% and the pregnancy index was 100%. The percentage of pre and post-implantation loss were 1.96 and 7.48 respectively with the number of early resorption outnumbered the late resorption (0.56 ± 1.0 and 0.36 ± 1.5 respectively). Out of 1,234 foetuses examined, only 5 foetuses (0.41%) presented with gross congenital malformation. The female SD rats obtained from the Institute demonstrated high fertility and pregnancy index with low incidence of resorption and malformation, therefore suitable to use for reproductive toxicity assessment.