Digestion trials were conducted to evaluate intake and digestibility of grass harvested at different dates. Silage was prepared from first-growth forage (predominantly timothy) which cutting dates; 4 June (vegetative, called early-cut) and 30 June (heading, called late-cut). The silage was fed to wethers at restricted and ad libitum levels of intake. The crude protein and crude fat of silage decreased with advancing maturity, while contents of fibre increased. DM intake of early-cut and late-cut silage were $99g/W_{kg}^{0.75};and;75g/W_{kg}^{0.75}$, respectively. In digestibility and TDN, significant differences (p<0.01) between early-cut and late-cut silage were found. There was no significant difference in DM digestibility of early-cut silage between restricted and ad libitum feeding, but DM digestibility was decreased markedly in ad libitum feeding that out of account in fecal condition. Digestibility of all composition in early-cut silage, except for hemicellulose, was not observed with increasing levels of intake. Digestibility of crude protein, NDF and hemicellulose in late-cut silage were decreased (p<0.05) in ad libitum when compared with restricted feeding. Results of this study suggest that digestibility of early and late forages harvested as silage varies with levels of intake. Thus, relationship levels of intake and digestibility must be considered cautiously.