 Reference Base  Clinical pathology parameters in white, black and norther... |
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Heerden, J. van; Keffen, R.H.; Kuhn, F.; Rogers, P.; Morkel, P.; Atalia, N.; Raath, J.P.; Kernes, D.J., 1994. Clinical pathology parameters in white, black and northern white rhinos: pp. 189-195, tables 1-4
 | In: Penzhorn, B.L. et al. Proceedings of a symposium on rhinos as game ranch animals. Onderstepoort, Republic of South Africa, 9-10 September 1994: pp. i-iv, 1-242 |
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| Location: |
World |
| Subject: |
Reproduction - Management methods |
| Species: |
African Rhino Species |
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Blood serum in African rhino. Serum progesterone concentrations in this investigation were found to be reliable indicators of pregnancy in black and white rhinoceroses but the wide range of serum concentrations observed would probably imply limited use in determination of the stage of pregnancy. More information on time of birth in animals in which serum progesterone concentrations in excess of 4 nmol/t have been found, may contribute to our understanding of the possible significance of observed serum progesterone concentrations. The wide fluctuation found in concentrations of metabolises of progesterone in the urine of different rhinos' as well as observed differences in urinary concentrations of hormone metabolises between different species of rhino' probably imply similar differences in serum hormonal concentrations. This probably even further belittles the value of single-serum progesterone concentration determinations. From our data and from data obtained from urinary steroid evaluations in black rhinos', it does however appear as if serum progesterone concentrations are very low during the first part of pregnancy, that concentrations may gradually rise during midgestation and thereafter until shortly before partus when there is a sharp decline. The possible influence of capture- and boma-stress on serum progesterone concentrations' has also not been investigated.
Single serum 1 7-9-oestradiol concentrations could not be related to pregnancy or non-pregnancy in the different rhino species in this investigation. Urinary estrone conjugate concentrations could likewise not be related to oestrus, postoestrus or early, mid- or late-gestation samples in black rhinos'. All phases of the reproductive cycle of the Indian rhinoceros could however be characterised by discrete concentrations of urinary estrone sulphate and pregnanediol-3-glucuronide'. Urinary hormone assays at this stage however appears to be an impractical method of investigation of the reproductive state of rhinos in South Africa.
The ability to confirm pregnancy in rhinos has many possible advantages: Known breeders could be identified and either withdrawn from the sale or offered for sale as pregnant animals. Pregnant animals should fetch higher prices at game sales. Pregnant animals should be considered at increased risk for chemical immobilisation, should receive optimal care when held in bomas or may even preferably be released. White rhinos in particular often do not adapt easily to captive conditions and pregnant animals are likely to abort. Recently 7 out of 9 white rhinos diagnosed as pregnant (based on serum progesterone concentrations) aborted and one gave birth to an apparently premature calf which died after 7 days. Known pregnant animals could also be released into the most appropriate habitat. Lengthy potential stressful transiocation and boma-training programmes should preferably not be undertaken in pregnant animals.
From limited observations and investigations to date it appears as if pregnancy should be assumed in an adult cow captured without a calf or if the calf is older than 18 months. Serum specimens should be collected at the time of capture for progesterone assay and if pregnancy is suggested, the cow should either be released (to prevent abortion or to avoid the calf been borne in captivity which may seriously jeopardise its chances of survival) or management should be upgraded and maintained at optimal levels at all times. A pregnant animal that does not want to feed in captivity is likely to abort.
Table 4. Progesterone concentrations in white and black rhino at different stages of pregnancy
Months of pregnancy Progesterone nmol/l Comments
Ceratotherium simum
2? 4.2 Aborted a 0/3 kg male foetus 3 months later
4 6
4? 6 Aborted a 2 kg male foetus 3 months later
4 5.1
4 10.5
5 501
7 88
8? 29 Aborted a 13 kg female foetus 2 months later
9 31 Calved 6 months later; 33 kg female calf that died
10 69
13 68
13? 60.1 Calved a month later; 38 kg male calf that died
13 75
15 70 Calved 2 weeks later; 48 kg male calf that died within 48 hrs
15 54
15 58
16 40 Calf died 7 days after birth; doy mass 50 kg
Diceros bicornis
6 50
8 61.3
9 >127
14 47.2
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