https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Delayed return to estrus following treatment with the gonadotrophin-releasing hormone agonist, Lucrin® Depot, in the tammar wallaby https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:36271 Notamacropus eugenii), to investigate whether Lucrin Depot (AbbVie), a GnRH agonist microsphere preparation, could (1) inhibit follicular development and estrus in a cycle reactivated by removal of pouch young (RPY) and (2) facilitate a synchronous return to estrus. Our results show that females reactivated with bromocriptine and RPY in early seasonal quiescence (July 2015) were inhibited by Lucrin Depot (0.125-0.5 mg kg -1, n=9) and unlike control females (n=3), did not copulate before Day 32 RPY. During the next breeding season (February 2016), the return to estrus after RPY was not delayed in animals treated with Lucrin Depot (=0.20 mg kg -1; n=12), and copulation occurred in treated and control females within the expected natural period after RPY (Day 26-33 RPY). In the following breeding season (March 2017), estrus was delayed in animals treated with Lucrin Depot (1.25 mg kg -1) on either Day 0 (Group A, n=6) or Day 10 (Group B, n=6) after RPY compared to control females (n=6). Estrus was detected in Group A between 39 and 66 days (55 ± 4.8d) and in Group B between 43 and 71 days (55.2 ± 3.9d) after RPY. In contrast, all control females underwent estrus and copulated as expected by Day 30 RPY. We conclude Lucrin Depot can inhibit ovarian follicular activity after RPY but as a standalone treatment does not result in a highly synchronous return to estrus in the tammar wallaby.]]> Wed 18 Mar 2020 17:07:30 AEDT ]]> Induction of synchronous oestrus but not ovulation after pre-treatment with the GnRH agonist, Lucrin® Depot, in the tammar wallaby https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:40069 3 mm; 14 ± 2.1 and 15.3 ± 2.1 follicles >3 mm in the CL-bearing ovary and contralateral ovary respectively. Similarly, females in the SOvn Group had 11.4 ± 2.4 and 17.4 ± 1.9 follicles >3 mm in each respective ovary. Uterine flushing and ovarian histology confirmed that females in LucrinþSOvn and SOvn Groups had not ovulated, but normal oocytes were present in the follicles. By comparison, the Control Group had ovulated with a single embryo being recovered from the uterus of 4 of 5 females. In contrast to all groups, females in the Lucrin Group showed follicular suppression (all follicles <1.5 mm) and an unstimulated reproductive tract. We conclude that a suppression plus stimulation regimen using Lucrin Depot followed by PMSG and hCG has the capacity to synchronise oestrus, and that 20 IU of PMSG stimulates the development of antral follicles >3 mm in both ovaries. However, a single 500 IU treatment of hCG on Day 23 RPY was not able to induce ovulation in the tammar wallaby.]]> Tue 05 Jul 2022 08:00:42 AEST ]]> Human chorionic gonadotrophin does not induce ovulation in the tammar wallaby https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:49559 Mon 22 May 2023 09:13:16 AEST ]]>