"Today on virtually any well managed dairy farm, forage analysis is a routine part of the forage and feed management program. There is no better way to monitor the crop from field to animal, if it is done properly. The importance of forage analysis in the feeding program is perhaps equaled only be obtaining the proper dry matter intakes fed to the dairy animal."
taken from: Forage Analysis by: R. Clinton Young, Extension Specialist

"Forage testing is an essential component in the design and evaluation of dairy feeding programs. The use of forage testing provides an opportunity to balance rations more accurately and economically. Forage analysis data is essential in trying to evaluate nutritional problems or inadequacies with a feeding program."
taken from: Obtaining Samples for Forage Testing by: L.E. Chase & C.J. Sniffen- Cornell University

Links for more information:
www.foragetesting.org
www.ansci.cornell.edu/tmolobs/soc161.pdf
www.ag.ndsu.nodak.edu/aginfo/dairy/Nutrition