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Oestrous Cycle - Anatomy & Physiology (view source)
Revision as of 09:13, 11 September 2008
, 09:13, 11 September 2008→Cyclic Changes in the Ovaries
** 0.8 cm from side to side
** 0.8 cm from side to side
* Transrectal ultrasound is difficult, because the ovaries are difficult to access. Therefore, folliculogenesis is much harder to visualise than in the cow.
* Transrectal ultrasound is difficult, because the ovaries are difficult to access. Therefore, folliculogenesis is much harder to visualise than in the cow.
* The ewe is similar to the cow, with 3-4 follicular waves in each oestrous cycle.
** If there are 3 follicular waves, two will occur during the luteal phase and one during the follicular phase.
* Even during anoestrus, dominant follicles will reach the same size as those present during cyclical activity.
* At the onset of oestrus, one or more follicles reach a size of 1cm.
** Follicular walls are thin and transparent.
* Rupture of the follicle at ovulation is preceded by the elevation of a small papilla above the general surface.
* Ovulation occurs through rupture of this papilla ~24 hours after the onset of heat.
* There is rapid development of the corpus luteum.
** Development is linear from day 2-12 after ovulation.
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