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.
Jpn J Vet Res
; 59(1): 31-9, 2011 Feb.
Article
en En
| MEDLINE
| ID: mdl-21476488
ABSTRACT
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 2001-2009. PSs were found to remain in the uterus at least until November of the year of parturition. CA detectability began to decline after September of the year of parturition. Monthly and age-specific proportions of CL-present females revealed that the post-mating season starts in August, and that the age of first ovulation is 4 years. These results indicate that the success rate of ovulation (SRO the probability that solitary/non-lactating mature females actually succeed in ovulation) can be estimated by calculating the proportion of CL-present females among > or = 4-year-old females without PSs captured from August to November; the early litter loss rate (ELLR the probability that parenting females lose all of their cubs [0-year-old offspring] before mating season) can be estimated by calculating the proportion of CL-present females among those with PSs and CAs captured in August or later. The estimated values of SRO and ELLR were 0.93 (62/67) and 0.27 (6/22), respectively.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Detección de la Ovulación
/
Placenta
/
Ursidae
/
Cuerpo Lúteo
Límite:
Animals
/
Pregnancy
País/Región como asunto:
Asia
Idioma:
En
Revista:
Jpn J Vet Res
Año:
2011
Tipo del documento:
Article
País de afiliación:
Japón