Become a Creator today!Start creating today - Share your story with the world!
Start for free
00:00:00
00:00:01
Interpreting anticoccidial sensitivity testing in poultry programs
802 Plays2 days ago
Dr. Claudia Osorio, associate advisor, Elanco, and Elizabeth Doughman, editor, WATT PoultryUSA and Poultry Future, talk through what good anticoccidial sensitivity testing looks like, how to interpret the results and how to use it responsibly in modern production systems.
Recommended
Transcript
Introduction and Sponsor
00:00:00
Speaker
Hello and welcome to the Future of Poultry podcast series.
00:00:12
Speaker
Hello, I'm Elizabeth Duffman, the editor of Watt Poultry USA and Poultry Future. This Future of Poultry podcast is brought to you by Alanco. Alanco Animal Health Incorporated is a global leader in animal health dedicated to innovating and delivering products and services to prevent and treat disease in farm animals and pests, bringing value for farmers, pet owners, veterinarians, stakeholders, and society as a whole.
00:00:39
Speaker
The Alango Pulture team works closely with producers and integrators to deliver comprehensive data-driven solutions that support bird health and production goals. Through a combination of technical expertise and on-farm support, Alango helps customers safeguard flock well-being while supporting long-term operational success.
00:01:00
Speaker
Learn more
Understanding AST in Coxidiosis Control
00:01:01
Speaker
at alanco.com. Joining us today is Dr. Claudia Osorio, Associate Advisor Alanco to discuss Anticoxidial Sensitivity Testing, or AST, and how producers can use it to help with the decision-making process when choosing which anticoxidials to use for toxidious control programs.
00:01:21
Speaker
Thanks for joining us, Claudia. Thank you for having me, Liz. Appreciate it ASD has been around for decades, but expectations have changed as production systems, products, and pressure on performance will evolve.
00:01:37
Speaker
From your perspective today, how do you define in a good anticoxidial sensitivity test? Well, that's a very interesting question. A good AST is one that generates reliable field-relevant data by accurately evaluating how a farm's current Imeria isolates respond to a specific anticoxidial drugs or programs. When aligned with field observations, it becomes a valuable tool for guiding effective coxidiosis control strategies.
00:02:12
Speaker
What are the non-negotiables and isolate collection, design, and endpoints to make the results design-worthy for a complex? The biggest non-negotiable is that the isolates represent the Aimeria population circulating the complex, not just one problem flock. That means collecting isolates across different performance levels in the complex, from used litter, not new litter, because I want an Oasis population that reflects real field exposure.
00:02:47
Speaker
from birds in the active cycling window, typically 21 to 28 days of age. But if there is a concern about early breakdown, I will also include younger birds around 14 to 18 days of age.
00:03:05
Speaker
Also when collected, focusing on the feed and water lines and the center of the house when bird activity is highest. Then, the trial design also matters.
Interpreting AST Data
00:03:17
Speaker
Proper controls, including an unmedicated challenge control, and when possible, non-challenge control. All products tested at label, thus using sufficient replication, typically 8 to 12 pens per treatment with 20 to 30 barts per pen.
00:03:36
Speaker
product selection include the current programme and the most realistic alternatives be careful about how products are grouped ionophores and chemicals behave very differently in a s t s finally the right endpoints are critical performance data weight gain feed conversion mortality and uniformity along with species specific lesion score using an standardized system we also need some measure of intestinal cycling of god integrity whether that is osis output or semi-quantitive assessment at the end of the day we need both pathology and performance to make confident programme decisions at the complex level
00:04:27
Speaker
One of the most challenging parts of AST is interpreting results that may be unclear, especially when lesion scores, recycling data, and performance don't all tell the same story. When you look at AST data, how do you interpret partial sensitivity or conflicting signals?
00:04:45
Speaker
Well, never interpret AST data in isolation or based on a single number. When I interpret partial sensitivity, I think in terms of a traffic light system. Well, green means good sensitivity, where performance is close to the non-challenge control, and lesions scores are clearly reduced.
00:05:09
Speaker
Red is poor sensitivity where performance looks like the challenge control and lesions scores remain high. And partial sensitivity usually sits in the yellow zone where performance is partially protected and lesions scores are moderate.
Recognizing Patterns and Changing Programs
00:05:30
Speaker
What specific patterns tell you if it's time to change programs? When it comes to changing a program, it's rarely about one number or one bad flock.
00:05:41
Speaker
It's about patterns. Seeing the same lesion trends, especially increasing e-maxima across multiple farms or health checks, increasing cycling seen on scrapings. When those findings line up with subtle performance drift and appear across several farms, not just one house, that is usually a program level issue.
00:06:07
Speaker
When multiple signs repeat across the complex, recommend changing the program. As more integrators move back forth between n NAE and NAIHM systems, the role of AST can look very different depending on the program in place.
00:06:22
Speaker
How have these fluctuations changed when AST is most useful, and how should producers think about interpreting AST results differently in NAE versus NAIHM programs?
00:06:35
Speaker
AST is useful in both systems, but for different reasons. In NAE systems, AST is most decision-worthy because it is focused on chemical products, including weak chemicals. Those products can lose sensitivity relatively quickly. AST helps detect early shifts before performance problems become obvious. In NAIH systems, interpretation depends heavily on product class. Ionophores reduce most but not all coccidia, allowing control leakage and immunity development. So, ionophores can sometimes appear to look weaker because ASTs are short-duration tests.
00:07:23
Speaker
that means ionophore ast results always need a strong field context strong chemicals are where ast is powerful because when resistance develops performance drops fast and ast mirrors that clearly Overall, AST today is not about finding a single answer or ranking products in isolation.
Integrating AST in Decision Frameworks
00:07:48
Speaker
It is about tracking sensitivity trends over time, especially for chemicals the that can lose effectiveness quickly, and using that information together with field lesions, scrapings, and performance to support informed long-term program decisions in both NAE
00:08:11
Speaker
and NAIHM systems. AST can be a powerful tool, but only when used correctly. To wrap things up, if you could give intubators one or two practical ways to implement antiproxidial sensitivity testing well, so they avoid overreacting to a single AST report, but still act in time to protect performance, what would those be?
00:08:35
Speaker
Well, first, treat AST as part of a standard decision framework, no one-time emergency test.
00:08:45
Speaker
That means having clear guidelines for when to run it, collecting isolates in a consistent and representative way, and interpreting results alongside field lesions, cycling, performance trends, and management changes. Second, be intentional about what you test and why.
00:09:08
Speaker
Ionophores and chemicals behave differently, so they should be evaluated with different expectations. And AST works best when it is used to answer specific questions, especially around chemical sensitivity and rotation
Conclusion and Call to Action
00:09:28
Speaker
timing.
00:09:28
Speaker
When used this way, AST helps integrators avoid knee-jerk reactions while still making timely program decisions to protect their performance.
00:09:41
Speaker
Thank you so much for sharing these insights. For more information on the solutions discussed here today, visit Olanco Animal Health at olanco.com. For more episodes of the Future Poultry podcast, please like and subscribe on wildpoultry.com or wherever you access podcasts.