A new focus on fiber in poultry: Is it a nutrient or antinutrient?

To explore the evolving role of fiber in poultry nutrition, AB Vista will host a dedicated symposium titled “A New Focus on Fiber in Poultry: Is it a Nutrient or Antinutrient?” at the upcoming 2025 Poultry Science Association (PSA) Annual Meeting in Raleigh, North Carolina. Taking place on July 16, this event will bring together industry-leading researchers and nutrition experts to examine the latest science and practical implications of fiber inclusion in poultry diets.

In this Q&A, we speak with two key AB Vista leaders driving this initiative, Dr. Tara York, Technical Services Director for North America, and Dr. Carrie Walk, Head of R&D. With decades of combined experience in monogastric nutrition, they offer insights into why it’s time to reassess fiber’s role in poultry production. From leveraging knowledge gained in swine research to redefining how fiber is measured and formulated, they shed light on where the science is heading, and what it means for nutritionists, producers, and the broader industry.

Please introduce yourself and tell us about your experience and your role at AB Vista.

Tara: My name is Tara York, and I serve as the Technical Services Director for North America at AB Vista. In this role, I lead a dedicated team that provides critical support to our key accounts across various areas, including feed milling, nutrition, and veterinary services.

With 29 years of experience in the poultry industry, and 16 of those with AB Vista, I’ve had the opportunity to work across multiple facets of animal nutrition, from amino acids and antioxidant preservatives to enzymes. Throughout my career, one thing has remained constant: a strong commitment to helping our customers overcome challenges in the field and achieve success.

Carrie: Hello. I’m Carrie Walk, and I have worked in the AB Vista R&D team for a total of 11 years now. My current role is the Head of R&D, where I lead, advise, and support an exceptional team of scientists. We work to develop new and next generation products and solutions in nutrition and gut health, as well as working closely with our central and regional teams to support our current products, solutions, and customers in the industry.

Can you tell us about the fiber symposium you’re hosting in July at the 2025 Poultry Science Association (PSA) Meeting in Raleigh NC? And why talk about fiber for poultry?

Tara: Yes, absolutely. AB Vista has been actively involved in exploring the roles fiber can play in animal nutrition for quite some time, particularly within swine production, as part of our understanding and development of the Stimbiotic concept. Last year we hosted a very successful fiber symposium at the Midwest Swine Meetings, which generated a lot of insightful discussion and questions.

Following that event, we began to receive increasing interest in the role of fiber in poultry nutrition. While research in this area continues to evolve, growing evidence suggests that fiber plays an important, though often underappreciated, role in poultry health and performance.

That’s why we decided to host this fiber symposium at the upcoming PSA Meeting in Raleigh. Our goal is to present the latest fiber research, stimulate discussion, and encourage further research and collaboration in this emerging area of poultry nutrition.

What beneficial roles do you believe fiber can play in the area of poultry nutrition/production?

Tara: To be completely honest, while research has been conducted on the role of fiber in poultry, we believe we’re still in the early stages of fully understanding its functional significance, and further research is clearly needed, particularly in terms of how to strategically incorporate it into diets for optimal outcomes. Historically, fiber has been viewed largely as a diluent in poultry diets, with limited nutritional value.

Carrie: However, emerging research is shifting that perspective. We believe this is because we are learning how to accurately and rapidly quantify fiber, the fractions and concentrations that constitute dietary fiber in our feed ingredients. With this information we can manipulate those fractions to support specific areas of nutrition and gut health; such as promoting beneficial bacterial growth and fermentation, improving gut function and integrity, and balancing fiber and protein to minimize protein fermentation and the diluent effects of dietary fiber, and optimize energy utilization.

What can you tell us about fiber’s role in poultry gut health and nutrient absorption, and how is this reshaping feed formulation strategies?

Tara: We're beginning to distinguish between different fiber fractions – particularly the roles of soluble and fermentable fibers. These substrates can be metabolized by the gut microbiota, resulting in the production of short-chain fatty acids (SCFAs) such as butyrate, acetate, and propionate. Of these, butyrate is particularly notable due to its trophic effects on intestinal epithelial cells, its role in modulating inflammation, and its contribution to improved gut barrier function.

How does fiber shape the poultry gut microbiome and what are the implications for health and efficiency

Tara and Carrie: There’s growing interest in how fiber and specific fiber fractions can influence microbiome composition and activity, gut transit time and fill, mucin production, and nutrient utilization, as well as mitigation of harmful bacteria. While much of this has been studied in monogastrics like swine, we believe poultry can also benefit – though more targeted, species- and production-specific research is needed to define optimal fiber types, inclusion rates, and interactions with other dietary components.

How is AB Vista contributing to industry understanding of fiber?

Tara and Carrie: As a leading global feed additive and enzyme technology company, AB Vista has long focused on the role of enzymes in improving feed efficiency and animal performance. One of our core enzyme technologies targets the breakdown of non-starch polysaccharides (NSPs), a key component of dietary fiber. In addition, we were the first to develop and bring to market a Stimbiotic – a product devoted to stimulating beneficial microbial fermentation and facilitating fiber utilization through the production of microbial enzymes. This work has naturally led us to explore the broader implications of fiber in monogastric nutrition.

We’ve made significant strides in swine nutrition, where our research and collaborations have helped shape the industry’s evolving view of fiber – from being seen as a simple diluent to a functional dietary component with implications for gut health, microbiota modulation, and immune function.

To support this, we’ve partnered with leading researchers to investigate the physiological effects of fiber, especially its fermentable fractions, on intestinal health, mucosal development, and systemic performance outcomes in both poultry and pigs.

In addition to research, we've developed practical tools for nutritionists, including a fiber calculator built from our extensive internal database. This tool allows nutritionists to calculate the various fiber fractions within their diet – such as % dietary fiber, NDF, ADF, Total NSP and Insoluble NSP – based on ingredient composition and inclusion rates. We've also advanced our NIR calibration capabilities to provide real-time fiber composition data across a broad range of feed ingredients.

Now, we’re working to translate and adapt this knowledge from swine to poultry, develop recommendations, and understand biomarkers to support our recommendations in the field. Although their digestive physiology differs, we believe many of the core principles we are learning in pigs could be applied to poultry, particularly around fermentable fiber and microbial-derived metabolites, which may offer similar benefits in poultry systems. Our goal is to help build the foundational understanding needed to better utilize fiber in poultry diets.

What is the latest fiber research that you’ll be sharing?

Tara and Carrie: Our speakers will be presenting a range of insights that we believe will be valuable to the audience. We will start the session by describing fiber and new methods for measuring fiber and its components in feed ingredients and diets. We’ll share knowledge gained from swine research and explore how these findings can be applied effectively to poultry nutrition. In particular, we will focus on assessing whether the fiber sources used in diets are delivering the intended benefits. This includes evaluating their impact on the microbiome, interpreting the results from a practical standpoint, and identifying key immunological markers that should be monitored – both in controlled research settings and under field conditions. Finally, we will conclude with a summary of our current knowledge to optimize fiber for performance, gut health and the environment, as well as asking about next steps and feedback from the audience.

How do you see the future of fiber implementation in poultry production in the U.S.?

Tara: Fiber has the potential to play a more strategic role in targeted areas of poultry production. One key example is in broiler breeders, which are often feed-restricted to manage body weight. While current diets may include ingredients like wheat midds or oat hulls to support satiety, we may be overlooking the functional benefits of fiber at specific stages of the rearing period. For instance, fiber sources high in insoluble fiber can hold more water, creating a bulking effect that enhances the feeling of fullness – an effect well-documented in sows. But what is the optimal fiber source to use in breeders to achieve similar results?

Additionally, the fermentability of fiber is another area of interest. Selecting fiber sources that can be fermented effectively may help reduce the prevalence of pathogenic bacteria. Previous research has shown that alfalfa, due to its high fiber content, can increase gastrointestinal transit time in poultry. This, in turn, promotes the production of short-chain fatty acids (SCFAs), which support gut health and can inhibit pathogen adhesion. Could this be a key strategy not just for breeders, but also for layers?

Finally, as we identify fiber sources with the greatest functional and health benefits, we must also consider their availability and scalability. Is the supply of these ingredients sufficient to meet the needs of the industry at a commercial level? Can we include ‘beneficial’ concentrations of these fiber fractions in poultry diets without creating diluent or detrimental effects to other nutrients? Do we need to reconsider our feed formulations to optimize fiber fractions and ratios, and what does this look like in practice? Still, a lot of questions remain. But we are making great progress in our understanding of fiber and how to harness the beneficial effects in both pigs and poultry – and we look forward to sharing more on this at the PSA meeting in July.