Reproductive biology of captive southern hairy-nosed wombats (Lasiorhinus latifrons). Part 1: oestrous cycle characterisation

Abstract

Southern hairy-nosed wombats (SHNWs: Lasiorhinus latifrons) do not breed well in captivity. To better understand their reproduction, daily urine samples were collected from nine captive females and analysed for volume (mL), specific gravity and a qualitative index of the number of epithelial cells, then stored at -20°C until samples could be analysed for progesterone metabolites (P4M). The mean oestrous cycle length was 35.1±2.4 days; however, individual cycle length ranged from 23 to 47 days. The mean luteal phase length was 20.8±1.3 days (range: 12 to 33 days). Urinary P4M was divided into four oestrous cycle stages: (1) early follicular phase, (2) late follicular phase, (3) early luteal phase, (4) late luteal phase, and analysed against urinary characteristics. During the late follicular phase, urine volume decreased (P=0.002) while urine specific gravity (P=0.001) and concentration of epithelial cells (P=0.004) both increased. The level of variability in oestrous cycle length suggests that some captive females may exhibit abnormal cycles; however, the changes in the urinary characteristics associated with the different stages of the oestrous cycle appear to offer a possible non-invasive means of monitoring the reproductive status of captive SHNWs.

Reproductive biology of captive female southern hairy-nosed wombats (Lasiorhinus latifrons). Part 2: oestrous behaviour

“…Urine samples were collected from nine females during both sampling periods; however, behavioural analysis was only conducted for seven females (eight individual datasets). Although urinary P4M was evaluated for all mature females within this captive breeding population (Swinbourne et al 2018), behavioural analysis for wombat F11 was not conducted because the animal was not under continual video surveillance in 2013. F6 was blind, and although the urinary P4M profile in this animal was representative of normal reproductive activity, she chose to remain in the indoor enclosure at all times and therefore did not exhibit normal wombat behaviours.…”

“…Urine samples, standardised for creatinine (Cr), were analysed for P4M using an enzyme immunoassay (EIA) previously described and validated for SHNW urine (Swinbourne et al 2017b). An iterative process, described by Swinbourne et al (2018), was used to determine baseline P4M values for individual captive female SHNWs. A sustained increase in P4M concentration above baseline for $3 consecutive days was defined as the onset of the luteal phase, and the first day of the sustained rise was classified as Day 0.…”