1) General Zoological Data
The genus Hippotragus contains three species: The extinct blue buck, the Sable antelope (H. niger) and the Roan antelope, Hippotragus equinus. Ill-defined subspecies of roan have been alluded to and their mitochondrial DNA was studied by Mathee & Robinson (1999). Information on the sable antelope is comprised in a separate chapter. The extinct "blue buck" ("Blaubock") found detailed description in the monograph by Erna Mohr (1967). These hippotragine species are distributed through Eastern Africa, but range to Ethiopia and South Africa. The roan antelope shares many features with the sable antelope but its horns are significantly shorter and its coat is somewhat lighter. Both sexes have horns and males are somewhat larger than females. Roan antelopes are found in more open environments than sable antelopes. Herds are dominated by a single male; their weight is between 150 and 300 kg (Nowak, 1999).
The population structure of roan and sable antelopes was studied with mitochondrial DNA control region analysis by Mathee & Robinson (1999). They concluded that the findings reflect the subspecific, locational origin of the roan populations, while in sable antelopes care should be taken during translocations of defined sable subpopulations. Wilson & Hirst (1977) presented a detailed monograph on ecology of South African Roan and Sable antelopes. Roan antelopes are not commonly seen in zoos according to Puschmann (1989).
General Gestational Data
Dittrich (1970) reported on the breeding of roan antelopes from the Hannover zoo. The length of gestation is from 268-280 days (Nowak, 1999). The single calf weighs 13-18 kg. The placenta weighed 1,900 g in the single specimen available.
No details currently exist on early gestational stages in roan antelope placentation. Mossman (1987) described a mesometrial cord insertion of Hippotraginae and that both uterine horns are used for placentation. The uterus, however, is described a "duplex", with Y-shaped cervical canal.
General Characterization of the Placenta
Details of fetal/maternal barrier
The feto-maternal border is typically epithelio-chorial with very tall subchorionic trophoblast and cuboidal trophoblast covering the villi. There are numerous binucleate cells, presumably producing placental lactogen as in other ungulates. The villi are sparsely branched and have large fetal blood vessels. There is no pigment in the subchorionic trophoblast.
The umbilical cord contained 4 vessels and a large allantoic duct. It measured 25 cm in length, had no twists and was mostly the allantoic portion of the cord. The cord of the second specimen was only 8 cm long.
7) Uteroplacental circulation
I am not aware of any published reports.
Trophoblast external to barrier
Lacking an implanted uterine placental specimen, nothing can be said about invasion of the uterus. It would be unusual, however, if in this ungulate endometrial infiltration occurs.
I am not aware of any studies.
Other remarks - What additional Information is needed?
Dittrich, L.: Breeding the roan antelope Hippotragus equinus at Hannover zoo. Int. Zoo Yearb. 9:119, 1970.
Griner, L.A.: Pathology of Zoo Animals. Zoological Society of San Diego, San Diego, California, 1983.
Gulland, F.M., Reid, H.W., Buxton, D., Lewis, J.C., Kock, R.A. and Kirkwood, J.K.: Malignant catarrhal fever in a roan antelope (Hippotragus equinus) at Regent's Park. Vet. Rec. 124:42-43, 1989.
Flach, E.J., Reid, H., Pow, I. and Klemt, A.: Gamma herpesvirus carrier status of captive artiodactyls. Res. Vet. Sci. 73:93-99, 2002.
Fordyce-Boyer, R., Sanger, T., Loskutoff, N., Kumamoto, A.T., Johnston, L. and Armstrong, D.: Comparative cytogenetic study of the Roan and Sable antelope, Hippotragus equinus and Hippotragus niger. Applied Cytogenet. 21:189-191, 1995.
Hattingh, J.: Comparative quantitation of the physiological response to acute stress in impala and roan antelope. Comp. Biochem. Physiol. A 89:547-551, 1988.
Kariuki, D.P., Injairo, R., Boyce, W.L., Wellde, B.T. and Ngethe, S.: Parasite survey of eight wild animals in the Ruma National Park. Ann. Trop. Med. Parasitol. 83 Suppl.1:115-118, 1989.
Mathee, C.A. and Robinson, T.J.: Mitochondrial DNA population structure of roan and sable antelope: implications for the translocation and conservation of the species. Mol. Ecol. 8:227-238, 1999.
Mohr, E.: Der Blaubock. Hippotragus leucophaeus (Pallas, 1766). Eine Dokumentation Paul Parey, Hamburg, 1967.
Mossman, H.W.: Vertebrate Fetal Membranes. MacMillan, Houndmills, 1987.
Nowak, R.M.: Walker's Mammals of the World. 6th ed. The Johns Hopkins Press, Baltimore, 1999.
Pospisil, J., Kase, F., Vahala, J. and Mouchova, I.: Basic haematological values in antelopes - II. The Hippotraginae and the Tragelaphinae. Comp. Biochem. Physiol. A 78:799-807, 1984.
Puschmann, W.: Zootierhaltung. Vol. 2, Säugetiere. VEB Deutscher Landwirtschaftsverlag Berlin, 1989.
Reid, H.W. and Bridgen, A.: Recovery of a herpesvirus from a roan antelope (Hippotragus equinus) Vet. Microbiol. 28:269-278, 1991.
Stafford, K.J. and Stafford, Y.M.: The anatomy of the omasum of some Zambian game species. Anat. Histol. Embryol. 22:342-347, 1993.
Wilson, D.E. and Hirst, S.M.: Ecology and factors limiting Roan and Sable antelope populations in South Africa. Wildlife Monograph # 54 in, J. Wildl. Management 41:1-111, 1977.
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