This document discusses the application of near infrared reflectance spectroscopy (NIRS) in the feed industry. NIRS is a rapid, nondestructive technique used to determine the protein, moisture, starch, lipid, and ash content of feed ingredients. It has been accepted as an official method for analyzing crude protein, acid detergent fiber, and moisture in feeds. NIRS can also be used to detect heat damaged proteins, fungal contamination, and adulteration in feeds. Calibrations are developed using statistical methods to relate NIR spectra to wet chemistry values. NIRS offers advantages such as rapid analysis, little to no sample preparation, simultaneous analysis of multiple components, and environmental friendliness.