Changes

== Age when Behavioural Traits are Expressed ==

== Age when Behavioural Traits are Expressed ==

* Generally acquire reproductive behavioural traits such as [[Reproductive_Behaviour_-_Copulatory_Behaviour_- Anatomy & Physiology#Mounting|mounting]] and [[Reproductive_Behaviour_-_Pre-copulatory_Behaviour_- Anatomy & Physiology#Erection|erection]] a long time before they acquire the ability to [[Reproductive_Behaviour_-_Copulatory_Behaviour_- Anatomy & Physiology#Ejaculation|ejaculate]] and produce spermatozoa.

* Generally acquire reproductive behavioural traits such as [[Copulatory Behaviour - Anatomy & Physiology#Mounting|mounting]] and [[Reproductive_Behaviour_-_Pre-copulatory_Behaviour_- Anatomy & Physiology#Erection|erection]] a long time before they acquire the ability to [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculate]] and produce spermatozoa.

* Behavioural traits are easy to determine, as [[Reproductive_Behaviour_-_Copulatory_Behaviour_- Anatomy & Physiology#Mounting|mounting behaviour]] and [[Reproductive_Behaviour_-_Pre-copulatory_Behaviour_- Anatomy & Physiology#Erection|erection]] can be easily observed.

* Behavioural traits are easy to determine, as [[Copulatory Behaviour - Anatomy & Physiology#Mounting|mounting behaviour]] and [[Reproductive_Behaviour_-_Pre-copulatory_Behaviour_- Anatomy & Physiology#Erection|erection]] can be easily observed.

== Age at First Ejaculation ==

== Age at First Ejaculation ==

* [[Reproductive_Behaviour_-_Copulatory_Behaviour_- Anatomy & Physiology#Ejaculation|Ejaculation]] is a complex process,requiring coordinated development of nerves, specific muscles and secretion of seminal fluids from the accessory sex glands.

* [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|Ejaculation]] is a complex process,requiring coordinated development of nerves, specific muscles and secretion of seminal fluids from the accessory sex glands.

* When development of all of these components occurs, [[Reproductive_Behaviour_-_Copulatory_Behaviour_- Anatomy & Physiology#Ejaculation|ejaculation]] can take place.

* When development of all of these components occurs, [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculation]] can take place.

* Generally the ability to [[Reproductive_Behaviour_-_Copulatory_Behaviour_- Anatomy & Physiology#Ejaculation|ejaculate]] preceeds the ability to produce sufficient spermatozoa to achieve [[Fertilisation%2C_Implantation_and_Early_Embryonic_Development_-Fertilisation- Anatomy & Physiology|fertilization]].

* Generally the ability to [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculate]] preceeds the ability to produce sufficient spermatozoa to achieve [[Fertilisation%2C_Implantation_and_Early_Embryonic_Development_-Fertilisation- Anatomy & Physiology|fertilization]].

== Age when Spermatozoa First Appear in the Ejaculate ==

== Age when Spermatozoa First Appear in the Ejaculate ==

* Males acquire the ability to produce seminal fluid and [[Reproductive_Behaviour_-_Copulatory_Behaviour_- Anatomy & Physiology#Ejaculation|ejaculate]] before spermatozoa are available to be [[Reproductive_Behaviour_-_Copulatory_Behaviour_- Anatomy & Physiology#Ejaculation|ejaculated]].

* Males acquire the ability to produce seminal fluid and [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculate]] before spermatozoa are available to be [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculated]].

* To determine when spermatozoa first appear, the ejaculate must be collected at least once per week.

* To determine when spermatozoa first appear, the ejaculate must be collected at least once per week.

** Easy to collect using an artificial vagina from the the boar, bull, dog, ram or stallion.

** Easy to collect using an artificial vagina from the the boar, bull, dog, ram or stallion.

* After behavioural characteristics have developed and the male is willing to [[Reproductive_Behaviour_-_Copulatory_Behaviour_- Anatomy & Physiology#Mounting|mount]] a receptive female/surrogate, frequent seminal collection is possible.

* After behavioural characteristics have developed and the male is willing to [[Copulatory Behaviour - Anatomy & Physiology#Mounting|mount]] a receptive female/surrogate, frequent seminal collection is possible.

** Enables determination of the age at which spermatozoa first appear in the ejaculate.

** Enables determination of the age at which spermatozoa first appear in the ejaculate.

* Even if the ejaculate contains spermatozoa, there may be insufficient numbers for optimum [[Fertilisation%2C_Implantation_and_Early_Embryonic_Development_-Fertilisation- Anatomy & Physiology|fertilization]].

* Even if the ejaculate contains spermatozoa, there may be insufficient numbers for optimum [[Fertilisation%2C_Implantation_and_Early_Embryonic_Development_-Fertilisation- Anatomy & Physiology|fertilization]].

* The presence of a threshold (minimum number) of spermatozoa is required.  These thresholds vary between species.

* The presence of a threshold (minimum number) of spermatozoa is required.  These thresholds vary between species.

* Reflect minimum seminal characteristics required to achieve pregnancy following [[Reproductive_Behaviour_-_Copulatory_Behaviour_- Anatomy & Physiology|copulation]].

* Reflect minimum seminal characteristics required to achieve pregnancy following [[Copulatory Behaviour - Anatomy & Physiology|copulation]].

* Practically, this is the most valid criterion for puberty in the male.

* Practically, this is the most valid criterion for puberty in the male.