Ultrasonography of the reticulum, rumen, omasum, and abomasum in 10 calves before, during, and after ingestion of milk

The reticulum, rumen, omasum, and abomasum were assessed via ultrasonography before, during, and 15, 30, and 120 minutes after feeding milk to 10 healthy calves. The ultrasonographic examinations were conducted using a 5.0 MHz linear transducer. Loops were recorded on video for further evaluation. The reticulum could be visualised before feeding in seven calves. Its appearance and pattern of contractions were similar to those in adult cattle, although the amplitude (1.7 ± 0.75 cm) and velocity (2.7 ± 1.34 cm/s) of the first contraction were smaller than in adult cattle. The reticulum could not be visualised in any of the calves during feeding as it was displaced cranially and laterally and therefore being obscured by the lungs as the abomasum expanded with the ingested milk. 2 hours post ingestion it remained obscured in 5 individual and was visualized again the other 5. The position and size of the entire rumen including the dorsal and ventral sacs and the ruminal contents were assessed. There were no ch...