Measurement of urinary oestrogens and 20 -dihydroprogesterone during ovarian cycles of black (Diceros bicornis) and white (Ceratotherium simum) rhinoceroses

Abstract

Summary. The development of a sensitive enzyme-immunoassay for 20\g=a\-dihydroprogesterone (20\g=a\-DHP) and its use in determining reproductive status in black and white rhinoceroses is reported. 20\g=a\-DHP in hydrolysed urine diluted in parallel to standards, and high-performance liquid chromatography (HPLC) confirmed the presence of 20\ g=a\ \ x=r eq-\ DHP and the absence of pregnanediol-3\g=a\-glucuronide(PdG) in urine collected from rhinoceroses after oestrus. Conjugated oestrone was identified by HPLC as the major urinary oestrogen in the black rhineroceros and conjugated oestradiol-17\g=b\ was the most abundant in the white rhinoceros. In African species, the black (Diceros bicornis), and northern (Ceratotherium simum cottoni) and southern (Ceratotherium simum simum) white rhinoceroses, excretion of 20\g=a\-DHP and oestrogen followed a cyclic pattern. Excretion of 20\g=a\-DHP was low before mating, at the time of peak oestrogen excretion, but high after oestrus. In the black rhinoceros, the follicular phase was 3\ p=n-\ 4 days and the luteal phase was 18 days, suggesting a cycle of 21\p=n-\22 days. The interoestrus interval in the northern subspecies of white rhinoceros was 25 days, which correlated well with the interval between peaks of oestradiol-17\g=b\ excretion. The interval between urinary oestrogen peaks in the southern subspecies of white rhinoceros suggested a cycle length of 32 days. This paper provides the first description of the pattern of excretion of urinary oestrogens and progesterone metabolites in African rhinoceroses.

Foreword: A perspective on the role of emerging technologies for the propagation of companion animals, non-domestic and endangered species

“…The ability to determine timing of oestrus, pregnancy status, sex, seasonality and overall reproductive status provides a powerful tool for breeders and wildlife managers. Development of non-invasive techniques for hormone monitoring (Hindle et al 1992;Schwarzenberger et al 1993) has facilitated sample collection in species where the acquisition of blood samples is difficult or counterproductive (e.g. stress-induced alterations in hormone levels).…”

Faecal Progestagen Profiles in Wild Southern White Rhinoceros (Ceratotherium simum simum)

“…Literature reports the existence of two different oestrous cycle lengths in captive white rhinoceros, one with a luteal phase length of 30-35 days and the other of 65-70 days. Only the shorter cycle is believed to be fertile (Hindle et al 1992;Schwarzenberger et al 1993;Radcliffe et al 1997;Patton et al 1999;Brown et al 2001). Also, periods of acyclicity have been found in captivity with a high incidence in both young and aged females (Brown et al 2001;Hermes et al 2006).…”

Non-invasive monitoring of ovarian function in Asian elephants (Elephas maximus) by measurement of urinary 5 -pregnanetriol

“…Concentrations (Hess et al, 1983;Brannian et al, 1988;Plotka et al, 1988; Mainka and Lothrop, 1990;Brown et al, 1991;Taya et al, 1991;Gross et al, 1991 (Mainka and Lothrop, 1990). Although measurement of urinary pregnanediol glucuronide or 20ct-dihydroprogesterone immunoreactivity has provided valuable information on ovarian function in a variety of mammalian species (see, for example, Loskutoff et al, 1986;Kirkpatrick et al, 1990;Hindle et al, 1992; Hodges, 1992 for review), our own unpublished observations (J. Hindle and C. Niemuller) Creatinine determination All urine samples were analysed for creatinine concentration after the initial thawing by the method of Hodges and Green (1989) and as previously validated for elephants by Ramsey et al (1981) and Poole et al (1984), to correct for variations in glomerular filtration rate of urine.…”

“…The assay sensitivity was approximately 0.1 mg ml-1 and the intra-and interassay coef¬ ficients of variation were 9.3 and 8.8%, respectively (« = 30 (Shackleton et al, 1980). Peaks from gas chromatography (GC) Pregnanetriol Immunoreactive 5 ß-pregnanetriol was measured using a microtitre plate EIA method similar to that described by Hindle et al (1992). The assay used the antiserum 5ß-pregnane-17,20a-diol-3a-yl glucuronide which was raised in rabbit against the immunogenic complex of 5ß-pregnane-17,20 diol-3a-yl glucuronide coupled to BSA (Samarajeewa and Kellie, 1985).…”

“…In the remaining two cycles, the rises were separated by one week (for example, one sample apart). (Hindle et al, 1992), gorillas (Hodges and Green, 1989), giant pandas (Hodges et al, 1984), white-tailed deer (Knox et al, 1992), killer whales (Walker el al, 1988) and macaques (Monfort et al, 1986). In contrast, however, the immunoreactivity associ¬ ated with these metabolites in Asian elephant urine is low and variable and their patterns of excretion do not correlate with ovarian events (J.…”