200 - Forage Cell Wall Organization, Complexes, and Components

Abstract: It has been nearly 31 years since the International Symposium on Forage Cell Wall Structure and Digestibility was held in Madison, WI. The text resulting from that symposium, first published in 1993, has been an invaluable resource for animal and plant scientists alike but, unfortunately, has yet to be updated. Symposium organizers recognized that there was "a critical lack of information on the chemistry of the cell walls of forage plants and especially how this chemistry relates to digestibility and absorption of the materials and how the digestibility can be improved through plant breeding". They proceeded to organize an excellent symposium that covered nearly every aspect of that broad topic. Whereas "fiber" (plant cell wall) always has been a mainstay in ruminant animal feeding, its importance in the areas of human and non-ruminant animal nutrition has now been realized as indicated by the extensive scientific literature published on the topic since the time of the symposium, and by the fact that dietary fiber is now considered an "essential nutrient" for the human. In this presentation, the components of the plant cell wall will be discussed and their organization within the plant defined. Their relationship to the gut microbiota will be highlighted as will those factors critical in determining accurate fiber concentrations in forages and fibrous ingredients using the latest fiber methodologies. Rather than being viewed simply as "roughage" or as "filler" or as an "anti-nutritional factor", cell walls now have a prominent role in all of animal and human nutrition, so understanding their characteristics at all levels becomes all the more important.