FURTHER OBSERVATIONS OF THE OVARIAN RESPONSE OF THE TAMMAR WALLABY (MACROPUS-EUGENII) TO EXOGENOUS GONADOTROPINS - AN IMPROVED METHOD FOR SUPEROVULATION USING FSH LH/

This study reports the development of an improved superovulation proto col in the monovulatory tammar wallaby, Macropus eugenii. Treatment wi th pregnant mare's serum gonadotrophin (PMSG; 10-20 IU) inhibited foll icle development in the corpus luteum (CL)-bearing ovary and only 2-3 eggs per female could be recovered after ovulation induction with gona dotrophin releasing hormone (GnRH; 3 X 30 mu g at 3-h intervals) or po rcine luteinizing hormone (LH; 4, 5 or 8 mg) 3 days after PMSG priming . Treatment with porcine FSH (8 X 6 mg at 12-h intervals for four cons ecutive days) was found to override this inhibition and resulted in th e recovery of 7-13 eggs per female after ovulation induction with porc ine LH (4 mg on day 5). For these animals, there was no difference in numbers of developing follicles, ovulation sites and eggs recovered be tween the CL- and non-CL-bearing ovaries. This FSH/LH protocol was eff ective in both cycling and non-cycling females, and multiple ovulation occurred from about 36 h after LH treatment. After LH treatment, eggs were recovered from the oviduct at 36-50 h. At 51-57 h, 12-25% of egg s were recovered from the uterus, and by 75 h all eggs were recovered from the uterus. It is concluded that the described FSH/LH protocol us ed results in higher ovulation success than the PMSG/GnRH method. (C) 1998 Elsevier Science B.V. All rights reserved.