Bulls with non-protruding penises must be checked immediately.
It is commonly noted at semen evaluation time when a bull is unresponsive to the probe. Occasionally, producers observe a bull trying to mount a cow and breed, yet the bull is unable to do so.
When examining a bull with a protrusion problem, look for everything from penile adhesions, to back injuries that can cause pain, to the penis’s physical inability to get erect. All can cause problems with reproduction.
Producers must pull the bull from the herd and check if it is a permanent injury.
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The causes can be hard to detect. Producers might notice lameness or swelling over the back, or there may be pain when the animal is given deep palpations. Sometimes painkillers are used. Often a wait-and-see approach is the only course of action, and then eventually a hand mating to make sure the problem has corrected itself.
These problems can’t be taken lightly. Often, when a back problem is the possible cause, the bull may attempt to mount, partially extend and then withdraw because of the pain along its back. It could be permanent, but extended rest can help.
Physical issues such as very large warts on the penis, cuts to the frenulum, adhesions on the penis or other deviations may prevent protrusion. These issues are often found at semen evaluation time and sometimes it is possible to feel adhesions, warts or other problems through the prepuce.
A veterinarian may sedate the bull to see if the penis can be made to protrude and determine whether it can be corrected. This may involve wart removal or cutting the frenulum or in some cases, breaking down adhesions from cut sheaths.
Cut sheaths often heal uneventfully but sometimes with severe cuts, scarring happens and prevents the bull from protrusion. I have seen instances of a zero pregnancy rate, which can be disastrous.
Some adhesions break down and release when the bull continually tries to mount, but the bad adhesions become permanent. In some instances, the penis will only protrude a small amount, in what is called short-penis syndrome.
For good fertility, semen must be deposited deep into the vagina so a penis that doesn’t fully protrude hurts fertility.
Often, when bulls will not protrude at semen testing time, it is simply the bulls fighting the probe.
In my experience, I have had more trouble with large herd sires where there is probably not enough stimulation. Also, I seem to have trouble with traditional Simmentals.
This doesn’t mean there is a problem. It means they are harder to stimulate with the electro-ejaculator.
Vets may try to stimulate the bull more to insure protrusion is possible. Others may get a helper to push on the sigmoid flexure from the back down between the bull’s legs while stimulation is happening.
If these actions fail, the bull can be tranquilized to check whether the penis drops out and there is no medical reason, or the vet can write there was no protrusion on the semen evaluation form.
If “no protrusion” is stated on the form, it is important to closely watch that bull breed to make sure it can protrude its penis.
As a precautionary note, if “no protrusion” is written on the semen form and the bull is to be insured, there will be exclusions made by the insurance company. Anything related to penile problems would be excluded because one would not know if those problems existed previously if the bull had not protruded on its semen test.
When you buy a bull and get the semen test, make sure protrusion has been approved. If not, ask the purebred breeder to clarify and watch the bull diligently at the first breeding for protrusion.
This often can repeat the next time semen evaluation is done.
Let’s hope “no protrusion” is rare on semen forms in the future.
Roy Lewis works as a veterinarian in Alberta.
