The accurate analysis of forage is paramount if the nutritive value to the ruminant animal is to be estimated. NIRS has the potential to accurately and rapidly evaluate the chemical and biological parameters of fresh silage. In many laboratory situations the pressure of proximate and specialized chemical analyses means that routinely, fresh forages have to be stored frozen (–20°C) before analysis. Research by MacRae et al., (1975) has shown that although the physico-chemical composition of high quality forages changed upon freezing and subsequent thawing there were no differences in the apparent digestibilities and total nitrogen remained relatively constant. The objective of this study was to examine the effect of freezing and thawing fresh silage on NIRS predictions.