== Age when Spermatozoa First Appear in the Ejaculate ==
== Age when Spermatozoa First Appear in the Ejaculate ==
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* Males acquire the ability to produce seminal fluid and ejaculate before spermatozoa are available to be ejaculated.
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* To determine when spermatozoa first appear, the ejaculate must be collected at least once per week.
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** Easy to collect using an artificial vagina from the the boar, bull, dog, ram or stallion.
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* After behavioural characteristics have developed and the male is willing to mount a receptive female/surrogate, frequent seminal collection is possible.
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** Enables determination of the age at which spermatozoa first appear in the ejaculate.
== Age when Spermatozoa First Appear in the Urine ==
== Age when Spermatozoa First Appear in the Urine ==