The young calf has a strong motivation to suckle, which is not satiated by providing milk in buckets. As a result calves develop oral vices, such as excessive licking, sucking and chewing of objects in their immediate environment. This can include the body parts of other calves, leading to rapid spread of infection in a group of calves (Smits and de Wilt, 1991). Such vices sometimes persist into adulthood, as udder sucking in the female or prepuce sucking and tongue rolling in the male (Albright et al., 1989). Normally the motivation for suckling declines once the calf starts ruminating, and it is therefore important to provide palatable food that is sufficiently fibrous to stimulate rumination (Sambraus et al., 1979). Hay or straw is often provided, but fresh grass could be more palatable and be eaten sooner and in larger quantities. This could allow the calves to be weaned earlier or concentrate allocation to be reduced.