On-Line Monitoring of Rumen Fluid in Milking Cows by Fibre Optics in Transmittance Mode Using the Longer NIR Region

Abstract

A simple near infrared (NIR) on-line transmittance measurement method for rumen fluid in cows was developed and tested with a specially-designed fibre optic probe. NIR spectra in the long wavelength region from 1100 to 1860 nm were used for analysing the chemical composition of rumen fluid in two selected cows. Partial least squares (PLS) calibrations were developed for the components considered to be important indicators of rumen fluid composition. The change in rumen fluid composition as a function of feeding was followed by spectral readings. The results indicate that NIR has the potential for on-line measurement of rumen fluid composition by using these specially-designed fibre optics.