Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus)

Johnston, S. D., Mcgowan, M. R., O'Callaghan, P., Cox, R. and Nicholson, V. (2000) Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus). Journal of Reproduction and Fertility, 120 1: 49-57. doi:10.1530/reprod/120.1.49

Author Johnston, S. D.
Mcgowan, M. R.
O'Callaghan, P.
Cox, R.
Nicholson, V.
Title Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus)
Journal name Journal of Reproduction and Fertility   Check publisher's open access policy
ISSN 0022-4251
Publication date 2000-09-01
Sub-type Article (original research)
DOI 10.1530/reprod/120.1.49
Open Access Status DOI
Volume 120
Issue 1
Start page 49
End page 57
Total pages 9
Editor C. Doberska
Place of publication Cambridge, UK
Publisher Journals of Reproduction and Fertility Ltd.
Language eng
Subject C1
300402 Animal Reproduction
780105 Biological sciences
Abstract As an integral part of the development of an artificial insemination programme in the captive koala, female reproductive physiology and behaviour were studied. The oestrous cycle in non-mated and mated koalas was characterized by means of behavioural oestrus, morphology of external genitalia and changes in the peripheral plasma concentrations of oestradiol and progestogen. The mean (+/- SEM) duration of the non-mated oestrous cycle and duration of oestrus in 12 koalas was 32.9 +/- 1.1 (n = 22) and 10.3 +/- 0.9 (n = 24) days, respectively. Although the commencement of oestrous behaviour was associated with increasing or high concentrations of oestradiol, there were no consistent changes in the morphology or appearance of the clitoris, pericloacal region, pouch or mammary teats that could be used to characterize the non-mated cycle. As progestogen concentrations remained at basal values throughout the interoestrous period, non-mated cycles were considered non-luteal and presumed anovulatory. After mating of the 12 koalas, six females gave birth with a mean (+/- SEM) gestation of 34.8 +/- 0.3 days, whereas the remaining six non-parturient females returned to oestrus 49.5 +/- 1. 0 days later. After mating, oestrous behaviour ceased and the progestogen profile showed a significant increase in both pregnant and non-parturient females, indicating that a luteal phase had been induced by the physical act of mating. Progestogen concentrations throughout the luteal phase of the pregnant females were significantly higher than those of non-parturient females. Parturition was associated with a decreasing concentration of progestogen, which was increased above that of basal concentrations until 7 days post partum.
Q-Index Code C1
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Agriculture and Food Sciences
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Citation counts: TR Web of Science Citation Count  Cited 43 times in Thomson Reuters Web of Science Article | Citations
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Created: Tue, 10 Jun 2008, 22:22:51 EST