Evaluation of reproduction control as a method of population management in Formosan macaque (Macaca cyclopis) - Conservation Medicine in Practice
Date Issued
2015
Date
2015
Author(s)
Yu, Pin-Huan
Abstract
The Formosan macaque (Macaca cyclopis) is a primate native to Taiwan As in other countries, conflicts between humans and macaques in Taiwan are a public health concern. This issue also covers other subjects like wildlife ecology, biology, zoonotic disease and veterinary medicine which involve the health of human, animal and ecosystem as a conservation medicine topic. Professionals from different area are needed to solve this problem thoroughly, effectively and balance. This study will starts from the aspect of veterinary medicine and conservation medicine and cooperate with professionals from biology, zoology and ecology, to investigate the applicability of different strategy in Formosan macaque and how does the spirit of conservation medicine conduct in this case. The Formosan macaque is considered one of the least known among the 19 extant species of the genus Macaca. Although studies of reproductive hormones and the ovarian cycle have been extensively conducted on other macaques, there is little information of Formosan macaques. The purpose of the first part of present study was to establish information about the reproductive physiology of Formosan macaques. From February 2013 to November 2013, 11 wild adult female Formosan macaques were selected for the study. Blood sampling from anesthetized macaques started on the day of first menstrual bleeding and was performed on days 4, 7, 10, 11, 12, 13, 14, 15, 16, 18, 20, 22, 24, and 27 afterwards. Laparoscopic examination was carried out every six days after the first day of menstrual bleeding, and daily during the periovulatory stage. The duration of the ovarian cycle, follicular phase and luteal phase was 29.2 ± 1.3 days, 13.3 ± 2.1 days and 14.1 ± 1.3 days respectively. In addition, changes in serum levels of sex hormones were coMPAred with endoscopic observations; the peak serum level of estradiol was 290 ± 12.7 pg/ml, and predicted an ovulation episode within 24–48 hours. Serum progesterone rose to a peak of 9.13 ± 1.78 ng/ml eight days after ovulation and then declined gradually. The data may be considered as reference values associated with the ovarian cycle in Formosan macaques. Hopefully, the study will be beneficial to further studies and the conservation of this endemic species in Taiwan. In the second part of present study, we evaluate noninvasive methods of reproductive control in Formosan macaque. All macaques in the study were tested for the cyclicity of serum level of progesterone and estradiol, vaginal smear and the swollen of perineal sex-skin to make sure all females are in normal ovarian cycle. 14 female adult Formosan macaques were divided into three groups: group one was injected with medroxyprogesterone acetate intramuscularly, group two was given levonorgestrel orally and group three was control group. The duration of ovarian cycle was 28.29 ± 5.3 days, there was cyclicity in vaginal smear and sex hormones. But the change in perineal sex skin was not prominent. Our study shows that after using MPA in Formosa macaque, serum estradiol and progesterone level were prominently suppressed, the average serum concentration of estradiol and progesterone were 23.07±4.99 pg/ml and 0.47±0.15 ng/ml respectively during the three months suppression. In the LNG group, only one individual demonstrated delay in ovulation. The average serum estradiol and progesterone concentration was 30.58±7.62 pg/ml and 0.22±0.02 ng/ml respectively during this period, which was prominently lower than control group. The estimated ovulation time was 59 days later than last day of medication. This study demonstrates that MPA intramuscular injection could successfully suppress estrus cycle for at least three months, and the efficacy of LNG is affected by the stage of ovarian cycle upon the time of dosing. Therefore, MPA is a more suitable choice for medical population control in Macaca Cyclopis in the field. In the third part of the study, we evaluated the safety and postsurgical outcomes of endoscopic salpingectomy for sterilization of female Formosan macaques (Macaca cyclopis) as a method of population control. Nineteen adult female Formosan macaques were included in our study. The fallopian tubes of each anesthetized macaque were cauterized and excised endoscopically using a 2.7-mm rigid endoscope system. We recorded the complications encountered, and objectively scored the amount of hemorrhage throughout the procedure. Postoperative ovarian function was evaluated by monitoring the serum levels of sex hormones in ten of the macaques for two ovarian cycles following the salpingectomy. Two to 13 months later, eight of the 19 macaques underwent laparoscopy for the objective evaluation of inflammation at the surgical sites on the fallopian tubes. No major anesthetic- or surgical-associated complications were observed in any of the macaques. The hormonal evaluation showed cyclic ovarian function after salpingectomy in all of the ten macaques examined, and the parameters were coMPArable to those of other macaque species. The long-term postoperative level of inflammation at the surgical site was minimal to low, and was lower than that reported for other tubal occlusion techniques used in macaques. The use of a 2.7-mm rigid endoscope for salpingectomy in macaques is safe and efficient, with fewer postoperative complications than coMPArable sterilization techniques. In this study, we cooperate with thirteen different public or private facilities which include three academic facilities. Together we conducted contraception in captive and wild macaque, release to the wild and follow up. Fulfill the concept one planet, one healthy of conservation medicine. The outcome of contraception is better with the usage of medroxyprogesterone acetae and endoscopic salpingectomy. However, multiple factors such as season, habitat and animals should be considered in field work, more experience is expected to fluent the protocol. In conclusion, hormone study is fundamental to many researches, we evaluate the suitableness of different contraceptive methods through the establishment of sex hormones of Formosan macaques. Endoscopic salpingectomy provides safe, effective and permanent contraceptive method. It is a more practical and efficient approach in the wild animal management.
Subjects
Formosan macaque (Macaca cyclopis)
conservation medicine
reproduction control
endoscopic salpingectomy
hormone
ovarian cycle
SDGs
Type
thesis
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