Evaluation of the efficacy of the synthetic analogue GnRH - deslorelin - as a reversible suppression agent of the cyclic ovarian activity in Callithrix jacchus

Abstract

The control of reproduction in captive wild animals is a necessary means for the management of these populations. The methods used have to look for reversible alternatives, easy to use and free of undesirable side effects. This project aims to evaluate the efficiency of the application of a synthetic GnRH agonist as a suppressant of ovarian cyclicity in Callitrichidae and to confirm its reversibility. For this purpose, five adult females, of the species C. jacchus, are being studied. They are paired as couples with an adult male of the same species. Phase 1: During the first 4 months, the couples will be kept separated by a wire mesh to prevent fecundation. The animals are to be monitored by methods of extraction and measurement of fecal metabolites of progesterone, with the intention of demonstrating the existence of ovarian cyclicity. The collection of the feces is always performed during the morning, three times a week. Phase 2: The couples are distributed randomly in two groups: Group "Deslorelin" (D) with three couples, and Group Control (C), with two couples. After restraining and under general anesthesia, the females in Group D, will be implanted with a subcutaneous implant containing 2,35 mg of Deslorelin acetate, while the animals in Group C, will be equally anesthetized, but without receiving any implant. During the next 3 months all the females from both groups will be kept separated from the males and as described in phase 1, feces will be collected during the morning, three times per week. It is the objective during this phase to demonstrate the suppression of the ovarian cyclic activity of all females in Group D only. After this period, all females will be anesthetized and the implant removed from the animals of group D, initiating phase 3. In this final phase, all females from both Groups (D and C) will be monitored with similar protocols, for a period of 3 months, with the aim to demonstratethe return of the ovarian activity of Group D and the maintenance of cyclicity in Group C.