NIR costs approximately half the cost of wet chemistry. Turnaround time is only 24 hours. Predicts the nutrient content, is not an actual measurement. Prediction equations need to vary for different feeds, growing locations and conditions etc. Equations for byproduct feeds are not readily available.
Equations are wide ranging.
Accuracy depends on matching the equation to the specific feed being tested. One light reading is used to predict all nutrients. If one nutrient is out of line, it is difficult to determine if a testing error is the cause. Wet chemistry will then be required to confirm the nutrient in question. NIR analysis is an inexpensive and rapid alternative best suited to analysis of hay, haylage, corn silage, high moisture corn and grains, since prediction equations for these feedstuffs are plentiful.