Difference between revisions of "Avian Breeding, Ovulation and Oviposition - Anatomy & Physiology"

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<big><center>[[Reproductive System|'''BACK TO REPRODUCTIVE SYSTEM''']]</center></big>
 
 
<big><center>[[Reproductive_System#Exotics|'''BACK TO EXOTICS''']]</center></big>
 
 
<big><center>[[Exotics_-_Avian_Reproductive_Anatomy_and_Physiology_-_Anatomy_%26_Physiology|'''BACK TO AVIAN REPRODUCTIVE ANATOMY & PHYSIOLOGY''']]</center></big>
 
 
<big><center>[[Exotics_-_Reproduction_in_the_Female_Avian_-_Anatomy_%26_Physiology|'''BACK TO FEMALE AVIAN REPRODUCTIVE ANATOMY & PHYSIOLOGY''']]</center></big>
 
 
 
 
 
 
== Breeding Cycles ==
 
== Breeding Cycles ==
 
* Classified according to length of cycle and the time of year when the species becomes reproductively active.
 
* Classified according to length of cycle and the time of year when the species becomes reproductively active.
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* Usually lay one or more eggs in a clutch and terminate laying to incubate the eggs.
 
* Usually lay one or more eggs in a clutch and terminate laying to incubate the eggs.
 
* Number of eggs per clutch and total number of clutches vary with species and season.
 
* Number of eggs per clutch and total number of clutches vary with species and season.
 
----
 
  
 
== Endocrine Control ==
 
== Endocrine Control ==
 
* In females, '''FSH''' is mainly responsible for follicular growth.
 
* In females, '''FSH''' is mainly responsible for follicular growth.
 
* Developing follicles produce '''Oestrogen''' from '''Theca and interstitial cells''' and '''Progesterone''' from '''Granulosa cells'''.
 
* Developing follicles produce '''Oestrogen''' from '''Theca and interstitial cells''' and '''Progesterone''' from '''Granulosa cells'''.
* Increasing levels of Oestrogen stimulate an '''LH surge''' to cause the [[The_Ovary_-_Follicles_-_Anatomy_%26_Physiology|follicle]]  to split and release the primary [[The_Ovary_-_Oocytes_-_Anatomy_%26_Physiology|oocyte]].
+
* Increasing levels of Oestrogen stimulate an '''LH surge''' to cause the [[Follicles - Anatomy & Physiology|follicle]]  to split and release the primary [[Oogenesis - Anatomy & Physiology|oocyte]].
* '''Oestrogen mobilizes calcium''' from the bone, increasing plasma concentrations for [[Exotics_-_Composition_and_Formation_of_the_Egg_-_Anatomy_%26_Physiology|egg formation]].
+
* '''Oestrogen mobilizes calcium''' from the bone, increasing plasma concentrations for [[Egg Composition and Formation - Anatomy & Physiology|egg formation]].
 
* '''Progesterone''' secretion continues to inhibit further ovulation and stimulate behavioural changes associated with '''broodiness and incubation'''.
 
* '''Progesterone''' secretion continues to inhibit further ovulation and stimulate behavioural changes associated with '''broodiness and incubation'''.
 
* '''Prolactin''' stimulates the production of '''crop milk''' in male and female columbiformes.
 
* '''Prolactin''' stimulates the production of '''crop milk''' in male and female columbiformes.
 
* '''Oviposition''' is controlled by '''prostaglandins and Arginine Vasotocin'''.
 
* '''Oviposition''' is controlled by '''prostaglandins and Arginine Vasotocin'''.
 
----
 
  
 
== Ovulation==
 
== Ovulation==
 
* Number of ovulations varies with species, mostly lay one clutch a year.
 
* Number of ovulations varies with species, mostly lay one clutch a year.
* [[Exotics_-_Anatomy_of_the_Female_Reproductive_System_-_Anatomy_%26_Physiology#Infundibulum|Infundibulum]] catches the [[The_Ovary_-_Oocytes_-_Anatomy_%26_Physiology|oocyte]], facillitated by the left abdominal air sac which tightly encloses the [[Exotics_-_Anatomy_of_the_Female_Reproductive_System_-_Anatomy_%26_Physiology#Ovary|ovary]].
+
* [[Avian Female Reproductive System#Infundibulum|Infundibulum]] catches the [[Oogenesis - Anatomy & Physiology|oocyte]], facillitated by the left abdominal air sac which tightly encloses the [[Avian Female Reproductive System#Ovary|ovary]].
* Once ovulation has taken place, the  [[The_Ovary_-_Follicles_-_Anatomy_%26_Physiology|follicle]] shrinks and regresses.
+
* Once ovulation has taken place, the  [[Follicles - Anatomy & Physiology|follicle]] shrinks and regresses.
* '''No [[The_Ovary_-Corpus_Luteum_-_Anatomy_%26_Physiology|corpus luteum]]''' remains, as there is no developing embryo to maintain.
+
* '''No [[Corpus Luteum - Anatomy & Physiology|corpus luteum]]''' remains, as there is no developing embryo to maintain.
 
 
----
 
  
 
== Oviposition ==
 
== Oviposition ==
 
* Expulsion of the egg
 
* Expulsion of the egg
* Contraction of the [[Exotics_-_Anatomy_of_the_Female_Reproductive_System_-_Anatomy_%26_Physiology#Vagina|Uterine shell gland (Vagina)]] with relaxation of abdominal muscles.
+
* Contraction of the [[Avian Female Reproductive System#Vagina|Uterine shell gland (Vagina)]] with relaxation of abdominal muscles.
 
* Minutes to hours
 
* Minutes to hours
 
** Cuckoos lay their eggs in seconds so they can get away before the host returns.
 
** Cuckoos lay their eggs in seconds so they can get away before the host returns.
  
 +
== Post-Lay ==
 +
 +
* Enters a non-breeding state whilst incubating and caring for the brood.
 +
* Resting ovary appears shrunken, similar to the juvenile [[Avian Female Reproductive System#Ovary|ovary]].
 +
* [[Avian Female Reproductive System#Oviduct|Oviduct]] regresses into an inconspicous, narrow tube.
  
----
 
  
== Post-Lay ==
 
  
* Enters a non-breeding state whilst incubating and caring for the brood.
+
[[Category:Avian Reproduction]]
* Resting ovary appears shrunken, similar to the juvenile [[Exotics_-_Anatomy_of_the_Female_Reproductive_System_-_Anatomy_%26_Physiology#Ovary|ovary]].
+
[[Category:Bullet Points]]
* [[Exotics_-_Anatomy_of_the_Female_Reproductive_System_-_Anatomy_%26_Physiology#Oviduct|Oviduct]] regresses into an inconspicous, narrow tube.
 

Latest revision as of 14:03, 5 July 2012

Breeding Cycles

  • Classified according to length of cycle and the time of year when the species becomes reproductively active.
    • Continuous breeders are reproductively active throughout the year e.g. Khaki Campbell duck.
    • Most wild species that breed in temperate, subarctic and arctic zones display yearly cycles.
  • Tropical or desert species may breed with cycles less than a year, at 6-month intervals or when conditions are favourable (opportunistic breeders).
  • Usually lay one or more eggs in a clutch and terminate laying to incubate the eggs.
  • Number of eggs per clutch and total number of clutches vary with species and season.

Endocrine Control

  • In females, FSH is mainly responsible for follicular growth.
  • Developing follicles produce Oestrogen from Theca and interstitial cells and Progesterone from Granulosa cells.
  • Increasing levels of Oestrogen stimulate an LH surge to cause the follicle to split and release the primary oocyte.
  • Oestrogen mobilizes calcium from the bone, increasing plasma concentrations for egg formation.
  • Progesterone secretion continues to inhibit further ovulation and stimulate behavioural changes associated with broodiness and incubation.
  • Prolactin stimulates the production of crop milk in male and female columbiformes.
  • Oviposition is controlled by prostaglandins and Arginine Vasotocin.

Ovulation

  • Number of ovulations varies with species, mostly lay one clutch a year.
  • Infundibulum catches the oocyte, facillitated by the left abdominal air sac which tightly encloses the ovary.
  • Once ovulation has taken place, the follicle shrinks and regresses.
  • No corpus luteum remains, as there is no developing embryo to maintain.

Oviposition

  • Expulsion of the egg
  • Contraction of the Uterine shell gland (Vagina) with relaxation of abdominal muscles.
  • Minutes to hours
    • Cuckoos lay their eggs in seconds so they can get away before the host returns.

Post-Lay

  • Enters a non-breeding state whilst incubating and caring for the brood.
  • Resting ovary appears shrunken, similar to the juvenile ovary.
  • Oviduct regresses into an inconspicous, narrow tube.