Gut feeling of chickens: exploiting the unique mechanism of digesta reflux to improve sustainability of poultry production


Birds are specifically engineered to fly and hence have a short, lightweight digestive system, designed to efficiently digest feed. This efficient digestion is believed to be facilitated by reverse flow of gut contents, a unique phenomenon called reflux. In this way, birds can retain their gut contents longer, thereby increasing time for degradation and absorption of nutrients.
The increasing world population and prosperity ask for a sustainable increase in poultry production, with increased use of food waste and agricultural by-products as feed resources. Optimal exploitation of reflux is pivotal to accommodate this shift in feed resources. To date, regulation of reflux is poorly understood, but likely involves mechanisms related to feed intake and dietary proteins and fibers. Particularly the role of various physicochemical properties of fibers is unclear.
Furthermore, I question, whether the genetic reflux potential is conserved in modern poultry breeds. Selective breeding resulted in a four-fold increase in meat- and a two-fold increase in egg-production since 1950s, coinciding with a profound increase in feed intake and a shift towards the use of highly-digestible/low-fiber feed ingredients. Considering the role of fibers in the regulation of reflux, modern chicken’s capability to utilize high-fiber resources could be compromised concurrently.
Understanding reflux is crucial to develop feeding and breeding programs for optimal exploitation of reflux. Using a novel approach, combining oral and cloacal (stable isotope-)tracer techniques, I aim to elucidate the reflux mechanism in poultry. I will study reflux in traditional and modern poultry breeds to reveal its quantitative importance for digestion. Subsequently, I will identify the role of dietary fibers in regulation of reflux, addressing the importance of physicochemical properties and interactions with proteins. Targeted transcriptome analyses of gut motility will provide valuable insights into the regulation of reflux. The results are pivotal to facilitate sustainable poultry production in future.


Project number


Main applicant

Dr. ir. S. de Vries

Affiliated with

Wageningen University & Research, Departement Dierwetenschappen, Diervoeding (ANU)

Team members

M. Breuer, M. Breuer, Dr. ir. S. de Vries


01/01/2018 to 31/12/2022