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Plasma prolactin concentrations during lactation, pouch young development and the return to behavioural oestrus in captive koalas (Phascolarctos cinereus)

K. BallantyneA,D, S. T. AndersonB, A. MucciC, V. NicolsonC and S. D. JohnstonA

ASchool of Agriculture and Food Science, University of Queensland, Gatton, Qld 4343, Australia.
BSchool of Biomedical Sciences, University of Queensland, St Lucia, Qld 4072, Australia.
CDreamworld, Dreamworld Parkway, Coomera, Qld 4209, Australia.
Corresponding author. Email:

Plasma prolactin (PRL) concentrations in captive koalas during lactation were determined by serial blood sampling. PRL concentrations were low (1.3 ± 0.1 ng mL-1; n = 5) during early lactation until pouch young (PY) began to emerge from the pouch (around Day 130) before significantly (P > 0.05) increasing between Day 161 and Day 175 (5.3 ± 1.0 ng mL-1). A significant (P < 0.001) peak in PRL (7.7 ± 0.6 ng mL-1) coincided with maturing young between Day 189 and Day 231. All females failed to exhibit any signs of oestrous behaviour until Day 268.8 ± 8.5 (n = 4), some 102 ± 19 days before PY were weaned following achieving target weights of 2.5–2.7 kg. Throughout lactation, plasma LH concentrations were relatively high (range 4.9–8.7 ng mL-1) and LH responses to exogenous gonadotrophin-releasing hormone were observed in all koalas at all times during lactation.

  • All
  • 2013
  • Biogeography
  • Biology
  • Chlamydia
  • Diet
  • Disease
  • Ecology
  • Ellis
  • Eucalyptus
  • Genetics
  • Habitat
  • Infection
  • Interventions
  • Koala
  • Lunney
  • Threats
  • Timms
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