dr.ir. S (Sonja) de Vries

dr.ir. S (Sonja) de Vries

Universitair Hoofddocent

Research expertise

My research focusses at quantitative nutrition of pigs and poultry, digestion kinetics, processing technologies, enzymes, and nutritional modelling, with special emphasis on dietary fiber and fiber-rich ingredients. Dietary fibers largely influence digestive process, as physicochemical properties of digesta, digesta transit, and microbial colonization, thereby affecting degradation and absorption of other nutrients. Hence, fibers play an important role in nutrition, and understanding the interactions between dietary fibers and digestive processes is crucial to predict the nutritional values of diets.

My research ambition is to understand the complexity of digestive processes in the animal and apply this knowledge to predict and improve the nutritional value of animal feed, ultimately aiming for sustainable and competitive use of feed resources without compromising animal performance and health. Currently, I am involved in several multidisciplinary projects, focusing at the challenges we face with the shift in feed resources and the increased fibre level of diets in circular agriculture; from pelleting technology to nutrient utilization and gut health. In 2017 I have been awarded a personal Veni grant from the Dutch Research Council (NWO) to study fundamental principles of the effects of fibres on digestive physiology in chickens, particularly hindgut reflux and uric acid recycling, to better understand how chickens cope with fibre-rich by-products and identify the role of genetics in the birds’ adaptation to such high fibre-diets. In this way my research is contributing to a sustainable and efficient use of resources to produce healthy and nutritional food for humans anticipating the increasing global demand for food the next decades. 


I obtained my BSc and MSc degrees in Animal Sciences and PhD degree in Animal Nutrition at Wageningen University & Research. My PhD research focused on the degradation of fibers in pigs and poultry, with special emphasis on Dried Distillers Grains with Solubles (DDGS) and rapeseed meal; two agricultural by-products that are widely used as animal feed ingredients. This work was part of a joint project between the Animal Nutrition Group and Laboratory of Food Chemistry, supervised by Prof. Dr ir W.J.J. Gerrits, Dr ir M.A. Kabel, and Prof. Dr ir W.H. Hendriks. Since then, I have been working on the nutritional characterization of fibre-rich ingredients and our understanding of their fate in the digestive tract of animals, with the aim to increase the use of agricultural by-products in animal feed. First at the Ingredient Research Centre of Trouw Nutrition R&D and since 2015 as Assistant and later Associate Professor at the Animal Nutrition Group of Wageningen University & Research.