The calves were given free access to hay, concentrates
and water. During three morning feeding sessions, each separated by 48 h, all calves were offered larger meals. The offered amounts were calculated according to the within patient 3-level Response Surface Pathway(RSP)design.Themilkgivenonthethreetestdays contained a contrast medium (barium sulphate),
and the animals were radiographed before, during andimmediately after intake to reveal whether milk entered the rumen.