Projects for PhD candidates with a scholarship

The Animal Nutrition Group is initializing different PhD projects. On these projects we like highly skilled and motivated candidates with a scholarship from their home country. Moreover, candidates should have passed an English qualification test. There are projects on all kinds of animals, including pigs, poultry, cattle, pets and fish and on all aspects of nutrition and physiology. If you are interested and qualified, have a look at the list and contact the responsible scientist.

Cecal protein fermentation in poultry

Poor enzymatic protein digestibility and overfeeding of protein results in the presence of undigested protein in the ceca of broilers. In addition to these proteins not being available for utilization by the bird, this undigested protein also becomes substrate for proteolytic fermentation with a subsequent change in microbial composition, colonization of pathogenic bacteria and the production of metabolites and toxins. The first objective of this project is to understand gut health better by evaluating the impact of pre-cecal undigested protein on microbial activity, proteolytic fermentation, intestinal health and performance of piglets and broilers (PhD-candidate in place). A second objective is to study transgenerational effects in poultry. A large body of evidence links maternal (mal)nutrition to the development of diseases after birth (in rodents and human). In poultry, it is known that dietary protein fed to broiler breeders can affect broiler offspring performance. When low quality protein sources are fed to broiler breeders, an increase in pre-cecal undigested protein can increase the production of (toxic) protein fermentation metabolites. To date, it is not known whether these metabolites are also transferred to the eggs and, subsequently, can affect broiler offspring gut health and performance. Therefore, this project aims to determine transgenerational effects of protein fermentation metabolites in broilers.

Contact: dr. Rene Kwakkel (

True ileal amino acid digestibility amino in dietary protein sources commonly consumed by humans

The protein digestibility corrected amino acid score (PDCAAS) is the method that until recently has been recommended by the FAO for determining the quality of proteinaceous foods consumed by humans (FAO/WHO, 1990). One of the main limitations of PDCAAS is that it is based on true faecal nitrogen digestibility rather than true ileal amino acid digestibility (Schaafsma 2005). Recently a new method (digestible indispensable amino acid score; DIAAS) has been adopted as the official method to asses quality of dietary protein by FAO (2013). DIAAS is based on the true ileal digestibility of individual amino acids, preferably measured in pigs, rather than true faecal nitrogen digestibility and for processed foods includes analysis of ileal digestibility of reactive lysine. To date, however, limited data are available on the true ileal amino acid digestibility and lysine availability of protein sources consumed by humans.

Contact: dr. Sonja de Vries (

Utilizing the growth potential of piglets in a novel, integrated, multi-litter housing system for sows and piglets

Within the setting of a novel, multi-litter housing system for sows and  piglets in which the transitions between gestation and lactation (sows), and the transition between suckling and weaning (piglets) is adapted to accommodate natural behaviour, this project aims to quantify the gap between growth performance of individual piglets and their growth potential; unravel the role of system, sow, litter and piglet factors in the size of this gap, focusing on factors affecting intake of milk and solid feed; and identify and test interventions to steer nutrient supply to minimize this gap.

Contact: dr. Walter Gerrits (

In-house testing for quality of pet foods

The quality of pet foods is vital for health and longevity of dogs and cats. Pet food companies therefore continuously invest in the development of their products by testing for various attributes including palatability, nutritional quality and intestinal health. Testing of pet foods for these basic attributes is generally performed under controlled conditions in animal facilities. In animal facilities nutritional quality is commonly assessed using apparent total tract digestibility assays and palatability of foods using acceptance and preference tests. Conditions can be tightly controlled and allow accurate assessment of the food under the conditions the animals are housed and cared for. To what extent obtained results are in agreement with the performance of the foods in practice remains unclear. This project aims to develop various in-house tests and compare the standard and in-house tests for assessment of the nutritional adequacy and quality of pet foods. The initial focus will be on the evaluation of nutritional quality and palatability of dog foods although also studies with cats could be undertaken.

Contact: dr. Guido Bosch (