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Oestrous Cycle - Anatomy & Physiology (view source)
Revision as of 09:03, 11 September 2008
, 09:03, 11 September 2008→Oestrous Cycle
=== Oestrous Cycle ===
=== Oestrous Cycle ===
* Short day breeders (oestrous cycles commence in response to decrease in day length).
* In Britain, sheep cycle from October-February, during which time there are 8-10 recurrent oestrous cycles.
* Ewe lambs and yearling ewes have shorter breeding seasons than older ewes.
* The length of the oestrous cycle is about 17 days.
* Duration of oestrus in most British breeds is ~30 hours and is at least 10 hours in immature ewes.
* In merino sheep, behavioural oestrus (heat) may last 48 hours.
* Ovulation occurs towards the end of oestrus.
=== Cyclic Changes in the Ovaries ===
=== Cyclic Changes in the Ovaries ===