ABSTRACTThe seasonal pattern of digestible organic matter (DOM) and crude‐protein production ofLolium perenne, Cynosurus cristatus, Anthoxanthum odoratum, Festuca ovinaandAgrostis stoloniferacut to 3 cm at 6‐week intervals was studied at five sites ranging from 49 to 303 m above sea level in north‐west Lancashire for the years 1969–70.DOM production declined from 482 g/m2on the lowest site to 220 g/m2on the highest; similarly protein production declined from 142 g/m2to 73 g/m2. Small but significant differences in the percentage of crude protein occurred only ia 1970, whereas DOM as a percentage of DM in the various species differed considerably between sites in both years. The significance of the results and the seasonal fluctuations in production are di