For example, corn silage is most accurately analyzed with a calibration equation developed for corn silage and not a calibration equation developed for alfalfa haylage. Keep in mind that laboratory monitoring practices increase the cost of the analysis. Asking these 6 questions will help evaluate a laboratory and is one way to become more knowledgeable about purchasing analytical services. Laboratories generally report results of analyses as a single number. The amount of this variation will differ from lab to lab and from method to method.
Variation is usually much higher for fiber measurements than for crude protein measurements.
South Dakota State University Agric.