Prompted by this article, which discusses the low number of bulls who sire US dairy cows.

How do semen companies extract semen from bulls?

The procedure to extract semen from humans is simple enough, but I'm struggling to picture a lab operator masturbating a fully grown bull until it ejaculates to collect semen. Is there some kind of specialized equipment involved? What does the operating procedure look like?

  • $\begingroup$ iirc they have a big fake cow with a hole in the rear end so when the bull mounts it, the semen can be collected. $\endgroup$
    – Tom Sol
    Commented Oct 18, 2019 at 4:59
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    $\begingroup$ @Tom: Any odds you might know the technical term? Search results for "Bull sex doll" mostly seem to be adult websites and stories about Devin Nunes' cow. $\endgroup$ Commented Oct 18, 2019 at 5:12
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    $\begingroup$ vivo.colostate.edu/hbooks/pathphys/reprod/semeneval/bull.html this should give you some idea. This site even has the speed of the ejaculate and other information $\endgroup$
    – Tom Sol
    Commented Oct 18, 2019 at 5:24

1 Answer 1


Colorado State University has two helpful pages that explain the main procedures (h/t Tom). Semen Collection goes through the 3 ways that are used to collect semen from animals.

Semen Collection from Bulls helpfully expands on bulls specifically:

Semen is most commonly collected from bulls in bull studs using an artificial vagina, as described below. Electroejaculation is an alternative method used with bulls that cannot mount or are too fractious for easy handling (e.g. range bulls). Finally, semen can be collected by message of the seminal vesicles and ampullae per rectum.

In a nutshell an Artificial Vagina (AV) uses thermal and mechanical stimulation to stimulate ejaculation. In the image below, the top item is an AV for use with rabbits and the bottom one is an AV for use with bulls. (The middle item is a director cone, which is used to collect semen from dogs.)

Artificial Vagina used for bull (bottom)

The procedure revolves around using a steer as a teaser to arouse and mount the bull, and then having an operator divert the penis the AV:

Illustration of collecting semen from a bull using an AV

As one of the pages helpfully explains:

Prerequisites to use of an AV are that the male be conscious, not significantly frightened of people, and more interested in ejaculating than in killing humans.

The main alternative for less docile bulls appears to be electroejaculation, which involves applying a series of short, low-voltage pulses of current to the pelvic nerves which are involved in the ejaculatory response. You then collect semen using a director cone much like the one in the image further up.

  • $\begingroup$ Good self-answer I could not have done it better. Judging by the pictures it is not a job for me though. $\endgroup$
    – Tom Sol
    Commented Oct 18, 2019 at 17:17
  • $\begingroup$ @Tom: Same here. Though to be honest, I'm not sure which of diverting a bull's penis into an AV or masturbating a dog with your bare hands and capturing the resulting ejaculate -- which is what the director cone depicted in the answer is for -- is most agreeable. $\endgroup$ Commented Oct 18, 2019 at 17:30

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