Computed tomography of the abdomen of calves during the first 105 days of life: I. Reticulum, rumen, omasum and abomasum.

Computed tomographic (CT) images of the reticulum, rumen, omasum and abomasum of five healthy Holstein-Friesian bull calves were compared with anatomical transverse cadaver sections of the same calves. The calves were scanned in the transverse plane from the 5th thoracic vertebra to the sacrum six times three weeks apart from birth to 105 days of age. Multiplanar reconstruction was used to create images in sagittal and dorsal planes. After subjective assessment of various anatomical structures, the rumen, omasum and abomasum as well as the ruminal strata (gas cap, fibre mat and fluid phase) were measured. After the last CT scan, all calves were euthanised, and four were kept at -18 °C in sternal position for 14 days. Transverse sections 1.0 to 1.5 cm thick were made from two calves and dorsal and sagittal sections were made from one calf each using a band saw. The CT images and anatomical slices were compared and the structures on the CT images identified. Very clear CT images were obtained from the reticulum, rumen, omasum and abomasum and there was excellent agreement between images and anatomical slices.