Cal Poly Bull Test, quality that makes the grade

By: Maria Chavez, Cal Poly Bull Test Assistant Secretary, junior animal science major with a minor in biotechnology

On my first visit to Cal Poly, after a campus tour, I wandered into the Animal Science offices and met Beef Cattle Specialist Dr. Trennepohl. As she explained the department’s commitment to the Learn by Doing philosophy, she spoke with enthusiasm about something called Bull Test. After talking with her, I knew that Bull Test was an annual student-run event, it was an opportunity to better understand the beef cattle industry, and that it had a place for me if I wanted to get involved. I left that meeting excited and ready to commit to Cal Poly, but I wouldn’t really understand what Bull Test was until I became involved as a student over a year later.

Bull Test 2017 Managers, Secretaries, and Enterprise Members

Every year in late May, consignors from California and beyond bring their bulls to Cal Poly where they will stay for five months to take part in the Bull Test. All bulls must be yearlings born within a three-month window to qualify for the test. Once “on test”, the bulls are all fed the same TMR (total mixed ration), and live side by side at the Cal Poly Bull Test Facility. These consistencies in age, nutrition, and environment create a baseline which allows for easier measurement of each bull’s merits based solely on genetics.

Over the following three months the bull’s ADG (average daily gain) is calculated. Additionally, the bulls are tested for semen quality, and ultrasound is used to determine meat carcass traits such as the amount of rib and rump fat, ribeye area, and percent IMF (intramuscular fat). All of this data along with each bull’s EPDs (expected progeny differences), or the set of numeric values assigned to an animal based on its genome, is translated into a score using the Bull Test Index. Each value correlates to a specific trait important to the industry. Some examples include yearling weight, calving ease, and marbling. The bulls who meet the threshold index score qualify for the auction in early October.


The test is student-run, offering credit as an Animal Science Enterprise course each Spring. Enterprise members are assigned to committees according to their skills and interests including event planning, marketing, media, and nutrition. Additionally, all enterprise members assist with daily checks in which they monitor water supply, fencing, and observe the bulls for any signs of injury or illness. Members also attend weigh days and help work the bulls in the chute while learning how to administer vaccines and treat common ailments.

In conjunction with this year’s sale, Cal Poly partnered with the National Cattlemen’s Beef Association to host a Stockmanship and Stewardship event. In the two days leading up to the sale, participants were able to attend educational workshops geared toward the modern-day beef cattle operation. Topics included meat fabrication and quality, Beef Quality Assurance, low-stress livestock handling, and herd health as well as stock dog and chute side demonstrations. Opportunities like this allow cattlemen and students to learn the latest livestock practices.

This year’s auction took place on October 1. In my mind and I am sure in many others, the day remains a blur. As soon as the buyers start to arrive, the sale seems to go by in only minutes. It’s a flurry of excitement and activity, but also the culmination of everyone’s hard work from the past 5 months. As the assistant secretary, my primary role was to help manage record keeping and paperwork. Throughout the day, I assisted with buyer number registration, bills of sale, and transportation documents. I also helped to set up the temporary office with the necessary computers and equipment to process the sales in real time. Other students were assigned to help the auctioneers at the sale block, sort bulls in the pens, record winning bidders, keep bulls moving through the sale ring, the list goes on and on. At the end of it all, I was truly amazed at all that we had accomplished. We had pulled off another successful sale day and Bull Test.bulltest6

Cal Poly Bull Test began in 1965 with just one pair of two-year-old Hereford bulls. This year’s test drew almost 200 bulls from four breeds. The Bull Test is an institution and a tradition, but it remains relevant in the ever-changing landscape of beef production. For consignors, the test provides a third-party confirmation of their bull’s genetic merits which adds value to their animal. For cattlemen, the test provides an opportunity to view and purchase bulls for their operation with confidence. However, in my experience, the test provides the greatest benefits to Cal Poly students. I’m grateful for the experience and education that the Bull Test has provided me, and look forward to seeing what new opportunities next year brings.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s