AbstractSix castrated male sheep were used in a two‐period crossover experiment to investigate the effect of mincing on the voluntary intake and digestibility of a silage. The silage was a high‐quality material, containing 68 % digestihle organic matter in the dry matter, prepared from S24 perennial ryegrass cut with a precision chop forage harvester and ensiled with the addition of 2.3 1 t−1formic acid as preser vative. The median size of particles in the unprocessed silage was 10–20 mm and in the minced silage 2–3 mm.The intakes of dry matter, organic matter and nitrogen for the minced silage were greater than for the unminced material, and for dry matter and organic matter intakes the differences were signi ficant (P005).It is concluded that with high‐quality silage diets there is a physical component in the mechanism for the control of voluntary food intake. It is suggested that for sheep, depressions in the digestibility of dietary constituents are unlikely to occur until silages are chopped to a median parti