Rations, of which the roughage portion was grass silage, or grass silage with hay at three different rates ([Formula: see text], [Formula: see text], and 1 lb. hay per 100 lb. body weight daily), were compared in feeding trials with lactating Ayrshire cows over a 3-year period at the Experimental Farm, Charlottetown, P.E.I. No significant differences were found in milk production, change in body weight, or butterfat content of the milk. There were progressive increases in total digestible nutrients and dry matter consumption as the rate of hay feeding increased. These increases were significantly greater for higher rates of hay feeding. Possible causes of these increases in consumption are discussed.