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Oestrous Cycle Pharmacological Manipulation - Anatomy & Physiology (view source)
Revision as of 12:45, 12 September 2008
, 12:45, 12 September 2008→Pharmacological: Prostaglandins
=== Pharmacological: Prostaglandins ===
=== Pharmacological: Prostaglandins ===
* Used to synchronize oestrus in groups of cows and heifers. Oestrus detection is difficult in this species, so this is advantageous for optimum timing of artificial insemination.
* Give two injections of PGF2α or an analogue such as cloprostenol at an interval of 11 days to a group of cows/heifers all at different stages of the oestrous cycle.
* 3-5 days after the second injection, all animals treated will come into oestrus and ovulate at about the same time.
* If only a single injection is given, conception rates are lower after subsequent artificial insemination.
* Two injections are required in order to ensure the prostaglandins are administered to all animals in a period where the corpus luteum is sensitive.
* To reduce cost and improve pregnancy rates, the following regime is used:
** All animals are injected with PGF2α on the same day and observed for oestrus during the following 5 days.
** Any identified in oestrus are inseminated
** Any not identified as being in oestrus receive a second injection of prostaglandin followed by artificial insemination.
** Any animals that exhibit oestrus following the first insemination are reinseminated.
=== Pharmacological: Progestogens ===
=== Pharmacological: Progestogens ===