There is ample evidence to show that the intake characteristics of silages harvested from the same sward can differ due to variations in digestibility and fermentation characteristics as influenced by additive treatment. In these studies animals were allocated to specific silages and had no choice of diets. More recently, Keady and Murphy (1994) have reported that cows have the ability to select their preferred silage within minutes, by either sight or smell, when offered access to a range of contrasting grass silages ad libitum and unsupplemented. The present study was designed to evaluate cows preferences for silages differing in fermentation and intake characteristics when offered concentrates varying in energy source.