Ruurd Zijlstra

Professor and Chair

Agricultural Life and Environmental Sciences

Agricultural Food and Nutritional Science

About Me


PhD, University of Illinois

Job/Research Area 

Swine & Carbohydrate Nutrition


Major Responsibilities/Research Interests 

My research interest is in ingredient evaluation and feed processing. The vision is to create a decision model that optimizes feed processing following ingredient evaluation. The end goal is to ensure a predictable performance of agricultural species. Within each feed ingredient, a range exists in quality characteristics that must be validated in animal models, but should be measured for a large number of samples using laboratory-based technologies. Subsequently, equipment, for example near infra-red reflectance spectroscopy, can feed quality following proper calibration. The range in quality is usually related to a change in factors such a fiber or other anti-nutritional factors that negatively influence nutrient digestibility or rate of digestion. Feed processing, including grinding, pelleting, expansion, extrusion, etc. can be used to reduce the negative impact of these factors and thereby improve digestibility characteristics.