Prediction of diet quality parameters of Rocky Mountain Elk via near infrared reflectance spectroscopy (NIRS) fecal profiling

Abstract

The objective of this experiment was to determine the validity of predicting the diet quality of Rocky Mountain Elk (Cervus elaphus nelsoni) by exposing a dried fecal sample to light energy (a spectrophotometer). The resulting spectra measured were then compared to the known wet chemistry of the diet to arrive at an equation for forecasting the crude protein (CP) and digestible organic matter (DOM) ingested by the elk. Forages were gathered from western ranges and blended to simulate plant species ingested representing various elk diet qualities at different seasons of the year. Feeding trials were begun during the summer of 1999 using the USDA Forest Service Starkey Unit’s herd of tame elk in northeast Oregon. Additional feeding trials were conducted at Center, Texas and College Station, Texas in the spring of 2000 and the summers of 2000 and 2001, respectively. In all feeding trials, 1 elk was fed 1 diet of known quality, ad libitum, for 8 days with fecal specimens collected on day 7 and day 8 for spectral scanning. Results indicate acceptable predictability (R2 = 0.95, SEC = 1.13 for CP, R2 = 0.80, SEC=1.73 for DOM) in forecasting the diet quality of elk, and thus it is concluded that NIRS is a valuable management tool in monitoring the well-being of captive and free-ranging elk.