Cattle Chat Podcast Summary

Episode: Guest: Dr. Stephan Hughes, KSU Resources, Bull Fertility
Date: December 19, 2025
Host: BCI Cattle Chat Team (Brad White, Dustin, Jason, Todd, Bob Weber)
Special Guests: Dr. Stephan Hughes (South Africa), Bob Weber (KSU, reporting from South Africa)

Overview

This episode of Cattle Chat centers on international perspectives in cattle veterinary practice, with a special segment recorded in South Africa. The main topics explore reproductive efficiency in beef operations, focusing on bull subfertility, challenges in fertility assessment, and practical advice on reproductive protocols such as prostaglandin administration. Insights from Dr. Stephan Hughes offer a global lens, reinforcing the shared challenges and solutions between U.S. and South African beef producers.

Key Discussion Points & Insights

1. International Connection: Cattle Chat Goes to South Africa

• Segment: [02:31]–[08:08]
• Highlights:
  • Bob Weber visits the LRF Stockman School in South Africa and interviews Dr. Stephan Hughes.
  • Dr. Hughes describes his cattle veterinary practice focused on both dairy and beef, with a special interest in reproduction (theriogenology).
  • Practice is located in the temperate, high rainfall Drakensberg region, with an emphasis on grass-based dairy and beef systems.
  • He listens to Cattle Chat and Bovine Science podcasts during his extensive travel between farms.

Notable Quote:

"We spend a lot of time in our vehicles. Probably 60 hours a month we spend traveling from farm to farm. So when I found Cattle Chat... what I liked so much about it was there was a group of like-minded guys that were just chatting about relevant cattle topics... I found them very informative."
—Dr. Stephan Hughes [06:14]

2. Value and Reach of University Resources

• Segment: [08:23]–[10:26]
• Highlights:
  • Discussion about the accessibility of K-State and land grant university resources (spreadsheets, webinars, extension publications) globally.
  • Cattle Chat and affiliated tools are used for continuing education and are adapted by producers worldwide.

Notable Quote:

"...if you go to the ag econ, agmanager.info you've got your spreadsheets, you've got different fact sheets, different decision tools... it's really a global product."
—Dustin [09:50]

3. Bull Fertility vs. Subfertility: Definitions and Practical Implications

• Segment: [10:26]–[17:11]
• Key Points:
  • Infertility is rare (bulls that get zero pregnancies); subfertility—bulls that underperform—is much more common and harder to detect.
  • Fertility metrics: A "fertile" bull should impregnate 25 healthy, cycling cows in 65–70 days (a metric favoring scale and profitability).
  • Subfertile bulls may breed cows, but not rapidly or efficiently enough for economic sustainability.
  • Bull breeding soundness exams (BSE) are tools, but not perfect predictors, especially in younger bulls.

Notable Quotes:

"I think actually subfertility is more common than infertility. Infertility would mean we turn bulls out with cows and they get no pregnancies. That's actually pretty rare."
—Bob [10:56]

"You have to look at bulls in both of those dimensions. Can they produce fertile semen and can they deliver that semen to the places that we need it to go?... It's not a lifetime test."
—Todd [12:12, 16:44]

4. Ongoing Evaluation of Bull Fertility

• Segment: [15:18]–[17:11]
• Highlights:
  • The importance of continuous monitoring, not relying solely on the initial BSE (especially in yearlings).
  • Bulls can develop new fertility issues with age or injury, making periodic reassessment crucial.

Notable Quote:

"There’s a perception that if a bull passed a breeding soundness evaluation as a yearling, that meant he was good for the rest of his career. And that's not a good assumption to make."
—Todd [16:17]

5. Listener Question: Prostaglandin Use Pre-Breeding

• Segment: [17:11]–[25:22]
• Discussion:
  • Pros/cons of using a single prostaglandin injection as part of a pre-breeding protocol.
  • Mechanism: Only effective in cycling cows (about 2/3 of cycling cows respond).
  • Realism in expectations: It may move up the average calving date slightly, but won't sync non-cycling cows or replace robust synchronization protocols.
  • Considerations: May temporarily increase bulls' workload if many cows come into estrus simultaneously ("bull power" required), and the timing relative to other pre-breeding vaccines (especially modified live IBR) matters, as mis-timed shots can negatively impact fertility by pushing more conceptions into later cycles.
  • Logistical complexity: The best time for prostaglandin is often five days after bull turnout—not always practical for all production settings.

Notable Quotes:

"About 2/3 will respond to an injection of prostaglandin if they are cycling. The reason is some of them are too early, the early CL does not respond..."
—Bob [18:49]

"If I get a bunch of cows that were otherwise going to cycle randomly... and I get a bunch of them to come in at a closer interval, I've now created a lot more work on a per-day basis for my bulls."
—Todd [20:49]

"The best way I have heard of people doing this is actually not to give it pre-breeding, but to give a prostaglandin shot day five after bull turnout."
—Todd [22:55]

6. Practical Recommendations and Wrap-up

• Segment: [25:22]–end
• Emphasis on discussing synchronization strategies with a veterinarian who understands the herd’s specific context.
• Use label directions and be mindful of vaccine and hormone timing interactions.
• Set realistic goals: Prostaglandin is modestly helpful for synchronizing early cycling cows but not a magic solution.

Notable Quote:

"This should be in a conversation between the veterinarian and the producer for their specific situation... Have realistic expectations. It's not going to move if they're not cycling. It's not going to help them."
—Brad [25:22]

Notable Quotes & Memorable Moments

• Dr. Hughes on Global Cattle Chat Reach:
  "Many of the topics, even though they’re North American based, are applicable to any cattle area in the world, and I found them very informative." [06:14]

• Todd on Defining Fertility:
  "A bull should be able to impregnate 25 healthy, actively cycling cows in a 65 to 70 day period... To me, that seems like a fairly rational benchmark." [12:12]

• Bob on Synchronization Math:
  "About 2/3 will respond to an injection of prostaglandin if they are cycling... But on day one of a breeding season, I do not expect 100% of the cows to be cycling." [18:49]

• Todd on Bull Workload:
  "If I get a bunch of cows... to come in at a more closer interval, I've now created a lot more work on a per day basis for my bulls." [20:49]

Timestamps for Key Segments

• Introduction and Tropical Drinks: [00:06]–[02:13]
• Interview: Dr. Stephan Hughes in South Africa: [02:31]–[08:08]
• KSU/Global Resources Discussion: [08:23]–[10:26]
• Fertility, Subfertility, and BSEs: [10:26]–[17:11]
• Listener Question: Prostaglandin Protocols: [17:11]–[25:22]
• Summary and Final Thoughts: [25:22]–end

Overall Tone

The conversation is conversational, collegial, and deeply rooted in practical on-the-ground experience. The hosts and guests use accessible language, mix scientific explanation with economic insights, and repeatedly underline the importance of continuing education and veterinarian-producer collaboration.

Useful for Listeners Who Haven't Heard the Episode

This summary covers the main international and practical themes, breaks down veterinary reproductive concepts, highlights best practices, and distills the action-oriented advice delivered throughout the episode. It preserves the technical precision while remaining accessible to producers, veterinarians, and students seeking to improve cattle reproductive management.