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Author Penzhorn, B. L.; van der Merwe, N. J.
Title Testis size and onset of spermatogenesis in Cape mountain zebras (Equus zebra zebra) Type Journal Article
Year 1988 Publication Journal of Reproduction and Fertility Abbreviated Journal J Reprod Fert
Volume 83 Issue Pages 371-375
Keywords mountain zebra; testis size; spermatogenesis
Abstract Testis mass of adult Cape mountain zebra stallions (mean 70·0 g) was appreciably less than that of other zebra species and domestic horses. The histological appearance of the testes of 11-, 24- and 29-month-old colts was typically prepubertal. Spermatogenic activity of a 4-year-old stallion obtained at the end of summer was at a very low level, while a 4·5-year-old stallion obtained 6 weeks after the winter solstice showed a marked increase in spermatogenesis compared with the 4-year-old. Stallions 6·5-19 years of age collected in different seasons all showed active spermatogenesis.
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Notes (down) from Professor Hans Klingels Equine Reference List Approved yes
Call Number Serial 1463
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Author Westlin-van Aarde, L.M.; van Aarde, R. J.; Skinner, J. D.
Title Reproduction in female Hartmann's zebra Type Journal Article
Year 1988 Publication Journal of Reproduction and Fertility Abbreviated Journal J Reprod Fert
Volume 84 Issue Pages 505-511
Keywords zebra; reproduction; ovaries; seasonality; progesterone
Abstract Ovaries, fetuses and plasma were collected from zebra mares shot in the Etosha National Park in Namibia between 15 and 25 August 1983. Ovarian weight was affected by reproductive status and most of the non-pregnant mares were anoestrous. The number of follicles varied between individuals and only pro-oestrous/oestrous mares had follicles larger than 20 mm in diameter. The largest follicle in pregnant mares was only 9 mm in diameter. Corpora lutea and corpora albicantia were found in non-pregnant as well as pregnant mares: 4 pregnant mares had only corpora albicantia. The presence of secondary corpora lutea could not be confirmed in any of the pregnant mares. Implantation was estimated to occur at around 73 days of gestation, and most mares (84%) had conceived between November and April. Peripheral concentrations of plasma progesterone during pregnancy varied from 0·5 to 2·4 ng/ml.
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Notes (down) from Professor Hans Klingels Equine Reference List Approved yes
Call Number Serial 1705
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Author Mitchell, D.; Allen, W. R.
Title Observations on reproductive performance in the yearling mare Type Journal Article
Year 1975 Publication Journal of Reproduction and Fertility Abbreviated Journal J. Reprod. Fert.,
Volume (Suppl. 23) Issue Pages 531-536
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Abstract Reproductive performance was studied in 137 yearling mares run with stallions in small groups for 3 months between June and August in 1968 to 1971 (four breeding seasons). Pregnancy diagnosis by repeated rectal palpation and qualitative tests for PMSG, showed that ninety-five mares conceived of which forty-four aborted spontaneously between days 30 and 160 of gestation. Laboratory examination of twenty-one aborted fetuses failed to show any infectious agents. Serial quantitative and qualitative tests for PMSG in aborting animals gave results similar to those observed in mares with normal pregnancies. Plasma progestagen assays showed marked individual variations although the loss of the conceptus was always associated with a drop in progestagen level. The high incidence of early pregnancy loss in these pubertal mares may also be related to immaturity, inadequate nutrition and physical stress.
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Notes (down) Approved no
Call Number Equine Behaviour @ team @ Serial 2378
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