On Level 1, five of the six calves drank all of the 4 l they were offered. One calf drank only 2.6 l (65% of the amount offered). This particular calf had a coughing spell during the meal and thereafter lost interest.
Fig. 2A (radiograph of the cranial abdomen of a standing calf) shows the abomasum before intake of the contrast milk, while Fig. 2B–D shows the gradual abomasal extension after ingestion of 2, 4 and 6 l of contrast milk, respectively.