Incidence of ovulation without coital stimuli in captive Japanese black bears (Ursus thibetanus japonicus) based on serum progesterone profiles.

نویسندگان

  • Tsukasa Okano
  • Sachiko Nakamura
  • Rumiko Nakashita
  • Takeshi Komatsu
  • Tetsuma Murase
  • Makoto Asano
  • Toshio Tsubota
چکیده

The purpose of this study was to ascertain whether or not Japanese black bears (Ursus thibetanus japonicus) are induced ovulators. The progesterone levels of female bears kept with a male and allowed to mate (n=2) and female bears allowed contact with a male through bars but not allowed to mate (n=6) during the mating season increased significantly in late October. Based on this result, the female bears were considered to have ovulated. Females isolated from males (n=3) were ovarioectomized after the mating season, and no corpora lutea were observed, indicating they had not ovulated. These findings suggest that Japanese black bears may be induced ovulators that ovulate with stimuli from males and without coitus at a high rate.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Changes in plasma gonadotropins, inhibin and testosterone concentrations and testicular gonadotropin receptor mRNA expression during testicular active, regressive and recrudescent phase in the captive Japanese black bear (Ursus thibetanus japonicus).

Male Japanese black bears (Ursus thibetanus japonicus) have an explicit reproductive cycle. The objective of this study was to clarify the variation of plasma testosterone, FSH, inhibin, LH levels and testicular gonadotropin receptor mRNA expression of male bears associated with their testicular activity. Notably, this study investigated peripheral FSH concentration and localization of gonadotr...

متن کامل

Hematological Profiles of the Formosan Black Bear (Ursus thibetanus formosanus)

93 *To whom correspondence and reprints requests should be addressed. Tel and Fax: 886-4-22206317. E-mail: [email protected] The Formosan black bear (Ursus thibetanus formosanus) belonging to the family Ursidae is distributed in the Central Mountain Range of Taiwan from broadleaf forests as low as 200 m to coniferous forests as high as 3500 m (Hwang et al. 2000, Chang et al. 2004). Fi...

متن کامل

Changes in blood glucose and insulin responses to intravenous glucose tolerance tests and blood biochemical values in adult female Japanese black bears (Ursus thibetanus japonicus).

The metabolic mechanisms to circannual changes in body mass of bears have yet to be elucidated. We hypothesized that the Japanese black bear (Ursus thibetanus japonicus) has a metabolic mechanism that efficiently converts carbohydrates into body fat by altering insulin sensitivity during the hyperphagic stage before hibernation. To test this hypothesis, we investigated the changes in blood bioc...

متن کامل

Immobilization of Japanese black bears (Ursus thibetanus japonicus) with tiletamine hydrochloride and zolazepam hydrochloride.

The effect of anesthetizing with a 1:1 combination of tiletamine hydrochloride and zolazepam hydrochloride (TZ) was evaluated in 75 Japanese black bears. TZ was administered to 43 captive and 11 wild, 8 captives and 13 hibernating captive bears at the doses of approximately 9.0 mg/kg (usual dosage), 18.0 mg/kg (high dosage) and 5.0 mg/kg (low dosage), respectively. Sufficient anesthetic effects...

متن کامل

Estimating the success rate of ovulation and early litter loss rate in the Japanese black bear (Ursus thibetanus japonicus) by examining the ovaries and uteri.

In order to develop a method for estimating the success/failure rates of reproductive processes, especially those of ovulation and neonate nurturing, in the Japanese black bear (Ursus thibetanus japonicus), we examined offspring status, corpora lutea (CLs), placental scars (PSs) and corpora albicantia (CAs) in 159 females (0-23 years old) killed as nuisances on Honshu Island of Japan during 200...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • The Journal of veterinary medical science

دوره 68 10  شماره 

صفحات  -

تاریخ انتشار 2006