ABSTRACT
The aim of this investigation was to describe the normal ultrasonic appearance of the intestinal loops of calves at different stages of their adolescence and at various intervals after suckling and to determine reliable reference values. Therefore the abdomen of 20 clinically healthy calves have been examined with a 5 MHz sector probe on the right and left flank of each animal and the exact position, the largest diameter, the thickness of the walls, the peristaltic activity and the appearance of the contents of each part of the intestines described. Most often, the pars cranialis duodeni could be seen ventral of the right costal arch as well as in the right flank, with younger calves it also showed in the left flank sometimes. The position could be changed considerably depending on the period elapsed since the last suckling time. The duodenum descendens and the duodenum ascendens could be traced in the right flank. The thickness of the wall was found to measure between 2 and 3 mm throughout the whole duodenum. The examination of the jejunum and the ileum was basically done in the right flank. In cases where the rumen was not yet fully developed visualization was also possible in the left flank. Most often these parts were seen in cross-section displaying permanent peristaltic activity. With the younger calves the large intestine could equally be traced in both flanks. In older animals it could be recognized as voluminous hollow organ filled with gas, or in case of the colon ascendens as garlandshape. In the jejunum and ileum as well as in the large intestine the thickness of the wall measured between 1 and 2 mm. Each part of the intestine showed an increase in diameter as the calves grew older. The peristaltic activity increased during two hours after suckling and during this time the echoing level of the contents was lower.
