Yes. Typically, there are two methods of analyzing feeds, wet chemistry and near infrared spectroscopy (NIR). The wet chemistry method is the standard to which the NIR method is compared and calibrated. Near infrared spectroscopy is a fast, efficient way of analyzing feeds and is used in certain circumstances when a representative calibration set for the feed being analyzed has been established using wet chemistry. Typically, forages such as silages and hays have been analyzed for protein, fiber, and estimated energy using NIR. Minerals and feeds without proper calibration, however, should be measured using wet chemistry. Because of feed type differences in total mixed rations (TMR), it is usually best to use wet chemistry when the TMR is analyzed.

Charles Stallings, Dairy Science, Virginia Tech