The “low milk fat” syndrome and “off feed” problems have long been associated with the use of rations incorporting a high proportion of starch based concentrate. These problems can be ameliorated by frequent feeding of concentrate, the use of out of parlour feeders or complete diets. Another approach has been to examine alternatives to cereal starch as the major energy source for concentrate supplements. Since few comparisons of concentrates containing a mixture of high quality fibre sources have been reported, the present trial was designed to compare concentrates based on cereal starch with those containing a mixture of high quality fibre sources when given with ad libitum grass silage from calving. An additional aim was to compare individual feeding through Calan Broadbent gates with groups fed forage at a self-feed clamp.