Validation of advisory models for the prediction of voluntary intake of grass silage by lambs and dairy cows

Abstract

Inaccurate prediction of silage intake is a major source of error in ration calculation. New routine methods such as electrometric titration (ET) and near infra-red reflectance spectroscopy (NIRS) have the potential to improve silage intake prediction (Offer et al., 1994). Development of new advisory models is slow because of the need to do large numbers of intake measurements. It is also essential that models are blind-tested (validated) on data not used for calibration. At SAC, sufficient animal intake data is now available for both calibration and validation although it is intended to continue to accumulate data for these purposes.