Abstract # 860 Poster # 49:

Scheduled for Thursday, August 18, 2005 07:00 PM-09:00 PM: (Cambridge/Oxford Room) Poster Presentation

Age-related Changes in Reproductive Efficiency in a Breeding Colony of Indian Origin Rhesus Monkeys (Macaca mulatta).

R. Harrison, C. Gagliarch, J. Geddis and H. M. Kubisch
Tulane National Primate Research Center, 18703 Three Rivers Rd., Covington, LA 70433, USA
     A retrospective analysis was performed to examine the reproductive pattern in a breeding colony of Indian origin rhesus monkeys (Macaca mulatta) at the Tulane National Primate Research Center. Records of 676 females with 6478 pregnancies occurring over 21 years were analyzed. Only the records of deceased females with at least 7 pregnancies were included to facilitate assessment of lifetime fertility. Data were analyzed by Least Squares ANOVA whenever appropriate. A total of 355 pregnancies failed in 275 females. Pregnancy failures were classified as stillbirth, spontaneous abortion, intrauterine death of the infant, and cesarean section-nonviable infant. Thirty failures occurred in the first pregnancy, 133 occurred during the last pregnancy. The ages of the females at those times ranged from 3.97 to 26.35 years with an average of 13.70 years and an average of 9.69 pregnancies. There was a significant increase in the percentage of pregnancies that terminated in females with advancing age, ranging from 5% in 4-year olds to 16.7% in 24-year olds, respectively. Similarly, the interval between births, which averaged 1.23 years, was significantly affected by age (P < 0.001), ranging from 1.3 years in 3-year olds to 3.3 years in 24-year olds. These results suggest significant changes in reproductive efficiency in ageing rhesus females. This research supported by NIH 2P51-RR000164-43 base grant to the Tulane National Primate Research Center.