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Oestrous Cycle Pharmacological Manipulation - Anatomy & Physiology (view source)
Revision as of 13:38, 12 September 2008
, 13:38, 12 September 2008→Pharmacological: Prostaglandins
=== Pharmacological: Prostaglandins ===
=== Pharmacological: Prostaglandins ===
* Used to induce luteal regression and subsequent cyclicity in cyclic ewes.
* Administration of PGF2α or its analogues during the period when there is a sensitive corpus luteum present induces oestrus 36-46 hours after injection.
* Ovulation will then occur shortly afterwards.
* In order to synchronize a group of ewes in randomly different stages of the oestrous cycle, two injections are required 8-9 days apart in order to ensure administration at a time when there is a sensitive corpus luteum present in all animals of the group.
* Uses are limited for a number of reasons:
** Having to give two injections is impractical under field conditions
** The induced oestrus leads to poor fertility, probably due to the limited exposure of the tract to progesterone.
** Prostaglandins can only be used in cyclic animals, not in seasonal anoestrus.
* It is usually only used in combination with progestogens.
=== Pharmacological: Melatonin ===
=== Pharmacological: Melatonin ===