Changes

* Detection of a [[The_Ovary_-_Follicles_- Anatomy & Physiology|'''follicle''']] and absence of a [[The_Ovary_-Corpus_Luteum_- Anatomy & Physiology|'''corpus luteum''']] by palpation or ultrasound examination of [[Female_Reproductive_Tract_-The_Ovary_- Anatomy & Physiology|ovaries]].

* Detection of a [[The_Ovary_-_Follicles_- Anatomy & Physiology|'''follicle''']] and absence of a [[The_Ovary_-Corpus_Luteum_- Anatomy & Physiology|'''corpus luteum''']] by palpation or ultrasound examination of [[Female_Reproductive_Tract_-The_Ovary_- Anatomy & Physiology|ovaries]].

* Crystallisation patterns in [[Female_Reproductive_Tract_-The_Vagina/Vestibule_- Anatomy & Physiology|vaginal]] mucus.

* Crystallisation patterns in [[Vagina and Vestibule - Anatomy & Physiology|vaginal]] mucus.

* Fall in body temperature prior to oestrus.

* Fall in body temperature prior to oestrus.

* Reduction in [[Female_Reproductive_Tract_-The_Vagina/Vestibule_- Anatomy & Physiology|vaginal]] pH.

* Reduction in [[Vagina and Vestibule - Anatomy & Physiology|vaginal]] pH.

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*** Nosing

*** Nosing

*** Mounting other females

*** Mounting other females

** Increase in [[Female_Reproductive_Tract_-The_Vagina/Vestibule_- Anatomy & Physiology|vaginal]] mucous (requires digital examination)

** Increase in [[Vagina and Vestibule - Anatomy & Physiology|vaginal]] mucous (requires digital examination)

*** Usually more pronounced in guilts than sows.

*** Usually more pronounced in guilts than sows.

==== Vaginal and Cervical Examination ====

==== Vaginal and Cervical Examination ====

By visual; examination of the [[Female_Reproductive_Tract_-The_Vagina/Vestibule_- Anatomy & Physiology|vagina]] and [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|cervix]] using an illuminated speculum, it is possible to detect the preovulation period.

By visual; examination of the [[Vagina and Vestibule - Anatomy & Physiology|vagina]] and [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|cervix]] using an illuminated speculum, it is possible to detect the preovulation period.

* In dioestrus, the [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|cervix]] is small, constricted and firm.

* In dioestrus, the [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|cervix]] is small, constricted and firm.

* In dioestrus, the [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|cervix]] and [[Female_Reproductive_Tract_-The_Vagina/Vestibule_- Anatomy & Physiology|vagina]] are pale pink and mucus is scanty and sticky.

* In dioestrus, the [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|cervix]] and [[Vagina and Vestibule - Anatomy & Physiology|vagina]] are pale pink and mucus is scanty and sticky.

* During oestrus, there is a gradual increase in vascularity of the genital tract and relaxation of the [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|cervix]] with dilation of the cervical os.

* During oestrus, there is a gradual increase in vascularity of the genital tract and relaxation of the [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|cervix]] with dilation of the cervical os.

* Approaching [[The_Ovary_-_Ovulation_- Anatomy & Physiology|ovulation]], the [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|cervix]] becomes very relaxed and its protrusion can be seen on the [[Female_Reproductive_Tract_-The_Vagina/Vestibule_- Anatomy & Physiology|vaginal]] floor.

* Approaching [[The_Ovary_-_Ovulation_- Anatomy & Physiology|ovulation]], the [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|cervix]] becomes very relaxed and its protrusion can be seen on the [[Vagina and Vestibule - Anatomy & Physiology|vaginal]] floor.

** [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|Cervical]] folds are oedematous

** [[Female_Reproductive_Tract_-The_Cervix_- Anatomy & Physiology|Cervical]] folds are oedematous

* [[Female_Reproductive_Tract_-The_Vagina/Vestibule_- Anatomy & Physiology|Vaginal]] folds glisten with clear lubricant mucus.

* [[Vagina and Vestibule - Anatomy & Physiology|Vaginal]] folds glisten with clear lubricant mucus.

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=== Clinical Methods and Assessments for Oestrus Detection ===

=== Clinical Methods and Assessments for Oestrus Detection ===

* Assessment of vulval softening

* Assessment of vulval softening

* Assessment of [[Female_Reproductive_Tract_-The_Vagina/Vestibule_- Anatomy & Physiology#Histology_and_Innervation|vaginal epithelial cells]]

* Assessment of [[Vagina and Vestibule - Anatomy & Physiology#Histology_and_Innervation|vaginal epithelial cells]]

* Examination of the appearance of the [[Female_Reproductive_Tract_-The_Vagina/Vestibule_- Anatomy & Physiology|vaginal]] wall.

* Examination of the appearance of the [[Vagina and Vestibule - Anatomy & Physiology|vaginal]] wall.

* Measurement of plasma progesterone concentration (detecting a rise in progesterone that preceeds [[The_Ovary_-_Ovulation_- Anatomy & Physiology|'''ovulation''']] in this species).

* Measurement of plasma progesterone concentration (detecting a rise in progesterone that preceeds [[The_Ovary_-_Ovulation_- Anatomy & Physiology|'''ovulation''']] in this species).