Tuesday, April 1, 2014

How to Fertility and Disease Test Bulls

We got to use our new silencer chute (hooray for a new chute!) for the first time last week.  We had 20 bulls to test and we did it in almost half the time that it took when we used the old one (I think The Rancher will keep it…).  It made testing bulls so much more exciting!  As if testing for STDs and fertility isn’t exciting enough!
There are regulations that cattle ranchers have to run by, mostly to prevent the spread of diseases through the herd and neighboring cows.  Before we can turn our herd bulls out with the cows, we have to test for trichomoniasis (trich)- a disease that will pass between cows and bulls as they breed.  This test is state regulated and has to be done by a vet.      
I feel bad for the bulls (just a little) because the test requires a few penile cells.  To get them they insert a small tube in the folds of the penis and wiggle it around to scrape off a few cells.  They are put into a solution to be sent off to be tested.  Each year we put tags in to show that the bulls have been trich tested and are good to go. 
These days, it is more of a precaution than an actual defense against the spread of trich. The vet was telling us that their clinic went out and tested 35,000 bulls and not one of them tested positive for trich.  We like to hear that!
Even if we didn’t test for trich, we would still bring the bulls in to test for fertility.  No one makes us do it, but we choose to test as part of our herd management.  When we know that there is a bull shooting blanks, we will pull him.  If he can’t perform he is costing us, mostly for the cows that don’t get bred (which won’t have a calf to sell). 
The vet starts with quick scrotal circumference measurement.  It also gives the vet a chance to palpate, or feel, for any deformities or hernias.  We’ve got to make sure that the family jewels are in good condition!
That’s the easy part…

In order to test fertility, we need a sperm count.  To get a sperm count, we need the bull’s semen.  To get the semen, we need the bull to ejaculate.  There’s two ways to go about it.  You can manually stimulate the bull by going inside the rectum and rubbing.  Or you can use an electrical pulsator in the rectum. 

We use the puslator, which by has been most commonly called the “Torpedo.”  Or The Rancher’s Sidekick called it a rocket (“Mom, what’s grandpa doing with that rocket?”).  You call it what you want…

Once the bull begins to ejaculate, the vet will catch about a tablespoon of semen.  He takes a few drops of the collected semen to put on a slide to be looked at under his microscope.  He can count the number of sperm and tell if there is enough to consider the bull to be fertile.  He can also see if there are any damaged or dysfunctional sperm.  Even if the pull is making sperm, damaged sperm still won’t do the job.  Once we get the all clear we send the bull on his way and start again with the next.

Not everyone will do fertility testing, just assuming that the young bulls are fertile and will pull them as they get older.  We’re mighty glad we don’t cull bulls that way… We found a three year old bull that didn’t pass his fertility test.  When this happens, we will generally do a second test a few weeks later.  The first test could have just been a rusty load or he really could be infertile.

Thanks to the Bear River Animal hospital for coming out and giving us another exciting lesson on the bull end of cattle reproduction!



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