In a previous study (Phillips and Leaver, 1983) grass silage was offered indoors overnight to dairy cows which were set-stocked during the day. The intakes of herbage DM were high in spring and declined thereafter, with silage DM intakes showing the reverse trend. This suggested that a single daytime stocking rate could be practised throughout the grazing season if silage was available ad libitum as a buffer feed. In this experiment, three daytime stocking rates were compared.

In a continuous design experiment lasting 24 weeks (17 April to 5 October 1983) 36 late winter calving Friesian dairy cows and heifers were housed and offered grass silage ad libitum overnight in a feeding passage. During the daytime the cows were set-stocked at 8, 10 or 12 cows/ha. Concentrates were fed at a level of 3 kg/day for weeks 1-16 and 22-24; 5 kg/day were fed for weeks 17-21.