By Glen L. Jensen, DVM
In veterinary school we cover so much information in a relatively short period of time where the goal is to create a very good foundation to continue to build on once you have graduated. I never got a chance to do a bull breeding soundness exam during the food animal rotation of my clinical portion of school. My first bull breeding soundness exams were performed with the doctor who hired me directly out of veterinary school.
One of the problems with this course of training is when in business, the person hiring you to perform a task is not going to invite you back if they don’t like the results of your services. We have all heard the saying, “The customer is always right.” I distinctly remember one of the bull producers saying to us after his bull sale and while looking at one of the bulls we did not pass and therefore he could not sell, “You cost me that bull.” I think he was the only one that failed, and it was only due to the fact that we could not get any semen from him.
When you hear that, even if you did everything you felt you could at the time, a person can’t help but to feel a little concerned. Then the mind starts to go through the whole process of second-guessing the entire situation, hoping you really did do everything you could to collect the semen sample, hoping he really isn’t too mad at you, wondering if maybe you should adjust your price. Even if you did do everything possible you still feel bad.
The irony is that the bull producer was expecting to sell 100% of the bulls we sent through the chute that day. To make our client happy we would run the bulls through as quickly as possible, this would help keep our costs down, we cut corners. Young bulls sometimes are difficult to collect. While trying to collect on one of them we had our sample, but it was obvious from the color that it was anything but a good collection. Placing the sample on the slide, then carefully adding the cover slip, hoping something was there. Sure enough, there was one or two swimmers. “That’s all we need” and declaring it a satisfactory potential breeding bull. We never looked at morphology on any bulls. If it wiggled it passed. We did write down a guess on morphology, but never actually checked. The more vigorous the movement the higher the morphology count was written down.
Looking back, I do not believe anyone was truly trying to mislead or cheat the system. It was just the way things were done. The bull producer really did believe 100% of the bulls he had invested so much in would and should pass the fertility exam. As veterinarians this was simply good business practices. We had plenty of reasons to justify how the exams were performed: The rancher can’t afford to pay us to take the time needed to perform every step with great detail, it would take too much time and even if he could afford it, there is a good chance he will go somewhere else if we raise our prices. When it comes to the morphology results (the structure of the cells), it is known that as motility (progressive movement of the sperm) improves so does morphology and the lower the motility the lower the morphology. Guessing puts us in the ball park and all we are really wanting is a pass. The numbers, even if not perfect, are not that important. But most important it was just the way things were done.
I later branched out on my own with a desire to not only tackle the world but to improve on what I had learned in my first job. I decided to improve on breeding soundness exams. My first bull was put in the chute, after carefully checking the scrotal circumference and all its contents. I put on a long glove and preceded to rectally palpate the accessory sex glands. As I looked up a curious face was nearby, “What are you doing, I don’t think he is pregnant.” Obviously, my past employer and myself were not the only ones skipping a few steps. For several years most producers questioned what I was feeling for when performing a rectal exam. They always expected an answer of “fertile” or “not fertile” with a simple glance in the microscope. No time or effort seemed to be needed to prepare a slide and count at least one hundred cells while classifying the types of normal or abnormal sperm observed.
Today producers know they are not going to have a sudden answer. Often I will place the sample on a slide, label it and set it aside to look at when I can relax a little, no rush or pressure from someone looking over my shoulder.
Later I purchased a phase contrast microscope with improved optics in an effort to continue improving my services. That is when a small lingering problem got bigger. The problem was I was doing too good of a job of finding a larger number of abnormalities than I had previously. It was not uncommon for bull producers to take their bulls to another veterinarian to get them “passed” after I had examined the semen and found too high a percent abnormal sperm to classify as satisfactory. With my new microscope I could better see things like clumped chromatin, knobbed acrosomes, and vacuoles in the head of the sperm cells. It didn’t take long until bull producers just quit using me; they could get a higher “pass” rate elsewhere.
Multiple studies in Canada performed by Dr. Barth and others in the U.S. continue to see results on yearling bulls with even a lower percent satisfactory classification than what I was seeing. But, how can a bull producer change from near 100% of the bulls they have raised to only 70% or less of bulls under 14 months of age with a satisfactory classification? It becomes heart wrenching when a bull producer, trying to be kind, lets you know they can’t use you because you fail too many bulls. What do you do? Lie? The research and the microscope have a different story.
This is about reproductive efficiency. The only way to improve a genetic pool is to put pressure in the direction you want it to go. It is not about fertile or not fertile. Very few bulls are truly sterile. Who is going to pay the piper? The bull producer or the bull buyer? How much does the hidden use of subfertile bulls, about 1 in 5, cost the individual producer and the industry as a whole?
Dr. Jensen practices mixed animal medicine in Castle Dale, Utah.