Cattle Chat Podcast Summary (June 13, 2025)

Episode Title: Research Update, Monitoring Cattle, Screwworm
Host: Dr. Brad White (A), BCI Cattle Chat team
Guests: Dr. Jordana Zimmerman (E, K-State PhD student, Brazil), Dr. Brian Herrin (G, Veterinary Parasitologist)
Main Theme: The episode explores cutting-edge cattle research, innovative monitoring methods for cattle health, and industry updates on screw worms—an economically important parasite affecting trade and livestock health.

Episode Overview

This episode focuses on three primary topics:

• A research update from Dr. Jordana Zimmerman on measuring rate of feed consumption in cattle and implications for pain and health assessment.
• Discussion on practical strategies for monitoring cattle health on pasture, balancing operational and economic factors.
• An in-depth look at screwworm outbreaks, eradication strategies, and the impact on livestock trade, with insights from Dr. Brian Herrin.

Key Discussion Points & Insights

1. Dr. Jordana Zimmerman's Research: Bovine Rate of Consumption Index ("BROCKI")

Segment: [03:26 – 11:04]

About the Guest

• Dr. Jordana Zimmerman, veterinarian from southern Brazil, joined Kansas State's BCI as a PhD student, researching animal welfare, pain, and health indicators.

Research Focus: Measuring Feeding Rate as a Health & Pain Indicator

• BROCKI stands for "Bovine Rate of Consumption Index," measuring how quickly cattle consume feed (kg/min).
• Traditional metrics focus on total intake; this approach adds the feeding velocity as an early indicator of pain or distress.

Notable Quote:

"Brocchi stands for bovine rate of consumption index, which means that we are kind of measuring the velocity in which the animals are eating, measured in kilograms by minute, in this case."
— Dr. Jordana Zimmerman [03:48]

Early Findings:

• Injured animals initially eat more quickly (perhaps to minimize standing), then slow down and visit the feed bunk less as they stop coping.
• Rates vary significantly between individuals (0.02 – 1.8 kg/min), suggesting both behavioral and genetic differences.

Notable Quote:

"At the first days, they ate more quickly and in lower visits at bunk... then some days later, they reduce this velocity when they are not coping any longer."
— Dr. Jordana Zimmerman [04:13]

Application & Future Use:

• Currently being validated for research; could help farmers identify pain/illness, improve welfare, and make management decisions (e.g., pain control, heat stress intervention).
• May integrate with technology-driven health monitoring (e.g., machine learning) for early BRD (Bovine Respiratory Disease) detection.

Notable Quote:

"Right now it's more research setting, but it can be extrapolated in the future for farmers."
— Dr. Jordana Zimmerman [06:09]

Technical Details:

• Average rate: 0.1 kg/min (about 3.5 oz), but varies dramatically.
• Potential for an individualized tracking approach over time.

2. Monitoring Cattle Health on Pasture: Cost-Benefit & Practical Approaches

Segment: [11:04 – 16:54]

Economic Perspective

• Balancing labor and time costs of frequent monitoring with the risk of missed health problems (higher treatment/preventative costs, mortality risks).
• More intensive grazing systems facilitate more frequent, incidental observation.

Notable Quote:

"There's trade offs you got to think through: how much time do I invest monitoring those animals... because there's cost associated with that."
— Dr. Dustin Pendell [11:42]

Management Strategies

• Prioritize close observation for high-risk groups (heifers near calving, post-surgery animals, weaning calves).
• Tie observation into regular workflow (e.g., while rotating pastures or delivering minerals).

Notable Quotes:

"If you can keep... the animals that have a higher chance to be sick... close to your home... you can have a closer look or more often see those herds."
— Dr. Jordana Zimmerman [13:36]

• Be prepared to adapt monitoring plans quickly when disease is suspected.

Field Tips & Behavioral Observation

• On pasture, initial herd observation is key before "interfering."
• "Watch for the animals that stay behind; differentiate between normal and abnormal behavior."
  — Dr. Jordana Zimmerman [16:08]
• Look for changes in grazing response, play behavior (in young animals), lameness, reluctance to get up.

3. Screwworms: Biology, Trade Impact, & Eradication Challenges

Segment: [16:55 – 23:35]

What are Screwworms?

• Adult is a fly; concerning stage is the larva (maggot), which feeds on living tissue—not just on dead tissue like most fly larvae.
• Historically eradicated from the US through the "sterile fly" program, now contained south of Panama.

Notable Quotes:

"These maggots feed on living, live flesh. And so they can just go through and eat through a body, creating bigger and bigger wounds..."
— Dr. Brian Herrin [17:18]

Recent Trade Impacts

• US imports ~1.2–1.3 million calves from Mexico annually.
• Discovery of screwworms led to import suspensions in late 2024 and again in 2025; tight domestic cattle supply raises feedyard prices and constrains processing.

Notable Quote:

"...if we're having fewer calves, we're going to see fewer animals going through feed yards being processed, and... upward pressure on prices."
— Dr. Dustin Pendell [18:57]

Eradication & Control Strategies

• Classic approach: mass-releasing sterile male flies. Females only mate once, so this stops population growth.
• Modern alternatives (genetic or molecular techniques) could supplement or replace irradiation.
• Recent local introduction (Florida) cost $1.5 million to control; national incursion would be much costlier and more complex.

Notable Quote:

"It got into a few deer and a few animals. And just that little focal introduction cost about $1.5 million to control at a local level."
— Dr. Brian Herrin [19:03]

Detection, Vigilance & Identification

• Adult flies resemble common house flies, with metallic sheen—difficult to ID visually.
• Larvae look like other maggots; key sign is deep, aggressively expanding wounds.
• If suspicious, contact USDA or a parasitologist for confirmation.

Notable Quote:

"If there's large numbers of maggots and you have a concern, I think it's worth contacting your USDA person, sending those in for identification."
— Dr. Brian Herrin [22:23]

• Remain vigilant, not overreactive; most summer maggots in the US are benign, secondary invaders.

Memorable Moments & Quotes

• Brad White on "Glitter Litter" (Icebreaker):
  "The product is called glitter litter, so cat litter, but it's basically glitter..." [01:21] – Provided comic relief before the research discussion.

• On Eradication Teamwork:
  "Cattlemen, state departments of AG, the US Department of AG... spent a lot of time and a lot of money to push this."
  — Dr. Bob Larson [20:29]

• Bob on Fly Castration (Lighthearted):
  "I just pictured Bob there doing some fly castration. Fly at a time." — Dr. Brad White [21:35]

Timestamps for Key Segments

• [00:52 – 01:09] – Dr. Jordana Zimmerman’s background
• [03:26 – 11:04] – Rate of Feed Consumption research (BROCKI index)
• [11:04 – 16:54] – Monitoring Cattle Health on Pasture
• [16:55 – 23:35] – Screwworms: Biology, Outbreaks, and Impact

Conclusion

This episode offers a blend of practical research and timely industry updates. Dr. Zimmerman’s work on feeding rate as a pain indicator introduces a potential new tool for cattle health management. The panel offers actionable advice for monitoring pasture cattle, emphasizing adaptability and awareness. Dr. Herrin’s screwworm overview connects real-world disease outbreaks to their far-reaching economic implications, stressing cautious vigilance and industry collaboration. The conversation is knowledgeable and approachable, making it accessible for producers, students, and anyone involved in beef cattle health.

Contact & Feedback:
Listeners are encouraged to reach out with questions or feedback at bcisu@edu.