Changes

* Secretions from the female reproductive tract that serve to sexually stimulate and attract males to the female.

* Secretions from the female reproductive tract that serve to sexually stimulate and attract males to the female.

* Vaginal and urinary secretions from females in [[Reproductive_Behaviour_-_Oestrus_Behaviour_- Anatomy & Physiology|Oestrus]] smell different to the male then secretions of females not in [[Reproductive_Behaviour_-_Oestrus_Behaviour_- Anatomy & Physiology|Oestrus]].

* Vaginal and urinary secretions from females in [[Oestrus Behaviour - Anatomy & Physiology|Oestrus]] smell different to the male then secretions of females not in [[Oestrus Behaviour - Anatomy & Physiology|Oestrus]].

* Pheromone is a volatile substance released to the outside of the body and perceived by the olfactory system and/or activated by the [[Reproductive_Behaviour_-_Pre-copulatory_Behaviour_- Anatomy & Physiology#Vomeronasal_Organ|'''vomeronasal organ''']].  Releasing pheromones can cause specific behaviour in the recipient.

* Pheromone is a volatile substance released to the outside of the body and perceived by the olfactory system and/or activated by the [[Reproductive_Behaviour_-_Pre-copulatory_Behaviour_- Anatomy & Physiology#Vomeronasal_Organ|'''vomeronasal organ''']].  Releasing pheromones can cause specific behaviour in the recipient.

* Males also produce sex pheromones.

* Males also produce sex pheromones.

** '''Boars''' produce specific substances that cause sows and guilts to become sexually aroused when they are in [[Reproductive_Behaviour_-_Oestrus_Behaviour_- Anatomy & Physiology|Oestrus]].

** '''Boars''' produce specific substances that cause sows and guilts to become sexually aroused when they are in [[Oestrus Behaviour - Anatomy & Physiology|Oestrus]].

** Two sexual attractants are produced by boars:

** Two sexual attractants are produced by boars:

*** '''Preputial pouch secretion'''

*** '''Preputial pouch secretion'''

* In many species, sexual readiness is accompanied by some form of unique vocalization ('mating call').

* In many species, sexual readiness is accompanied by some form of unique vocalization ('mating call').

** Cows increase bellowing during [[Reproductive_Behaviour_-_Oestrus_Behaviour_- Anatomy & Physiology|Oestrus]].

** Cows increase bellowing during [[Oestrus Behaviour - Anatomy & Physiology|Oestrus]].

** Sows display characteristic grunting associated with [[Reproductive_Behaviour_-_Oestrus_Behaviour_- Anatomy & Physiology|Oestrus]].

** Sows display characteristic grunting associated with [[Oestrus Behaviour - Anatomy & Physiology|Oestrus]].

** Queens often 'yeow' repeatedly to call the tom.

** Queens often 'yeow' repeatedly to call the tom.

** Mares and Ewes are comparitively silent.

** Mares and Ewes are comparitively silent.