Forage utilization is one of the most important topics in ruminant nutrition. This course will be given by leading scientists from the US Dairy Forage Research Center (Wisconsin, USA) and the Nordic countries. The course will focus on how forage cell walls factors limit digestion in ruminants. New and improved analytical methods for estimation of the quantity and quality of cell walls will be presented as well as technology to measure degradation and passage trough the gastrointestinal tract. Practical exercises with analytical techniques in vitro will give a deeper understanding to the theoretical presentations. Scientific articles will be presented and discussed to highlight important scientific progress in the area. Examination includes solving practical problems as written take home project.