Technical Note: Fecal NIRS equation field validation

Abstract

Seven trials, independent of data used to develop fecal near infrared reflectance spectroscopy (NIRS) equations, were conducted to validate previously developed fecal NIRS equations for prediction of forage diet crude protein (CP) and in vivo-corrected digestible organic matter (DOM) under field conditions. For both crude protein and digestible organic matter, strong relationships existed between conventional chemistry values of diet samples collected with esophageal-fistulated steers and NIRS predictions from fecal samples collected from intact, mature, Brahman x Hereford cows at 72 hour after grazing was initiated in trial pastures.