Progesteroonvlakke gedurende geslagsontwikkeling in lente-gebore Karakoelooilammers (Kort mededeling)

Author: A.S. Faure, G.J. Minnaar & J.C. Morgenthal
Year: 1989
Issue: 2
Volume: 19
Page: 87 - 89

Progesterone levels during sexual development in spring-born Karakul ewe lambs.

Four spring-born Karakul ewe lambs were pen fed to first lambing. Blood samples for analysis of progesterone concentration in peripheral plasma were taken on Mondays, Wednesdays and Fridays from these sheep between 14 to 240 days after birth. The progesterone concentration remained relatively low (< 0,5 ng ml-1) till puberty which occurred during their first breeding season, when it increased to introduce a luteal phase. One or two silent ovulations occurred before conception, following luteolysis. The duration of the luteal phases after the initial silent ovulation in the four ewes were 9, 8, 12, and 10 days with average progesterone concentrations of 1,1, 1,7.2,4, and 2,5 ng ml-1, respectively. In the present study no anomaly in corpus luteum function, which could contribute to the poor reproduction reported for this birth group, could be found in spring-born ewe lambs during their first breeding season.









Keywords: Ewe lambs, progesterone concentration, sexual development
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