Widespread adoption of sheep systems based on mixed swards of white clover and grass may result in conservation cuts with a high proportion of clover, which will affect the intake of the silage or hay. The effect of proportion of clover in silage on voluntary intake was measured by offering mixtures of clover and grass silage with clover proportions of 0, 0.20, 0.40 and 0.60 with (S) and without (U) a ration of 600 g fresh weight per day of a barley, soya and fishmeal concentrate to 78 Finn Dorset ewes. The concentrate was formulated to have a crude protein content (CP) of 160 g per kg DM with 30 g per kg DM derived from fishmeal. The silages were made separately in 1984, with formic acid added at approximately 3.51 per tonne, from uninterrupted spring growths of perennial ryegass (Loliua perenre cv. Melle) cut on 16 June and white clover (Trifolium repens cv. Blanca) cut on 17 July and both were chopped. Mixtures of the two silages were made for each individual ewe separately each day, immediately prior to feeding.