Villus atrophy in ruminal drinking calves and mucosal restoration after reconditioning.

The effect of reconditioning therapy on 7 chronic ruminal drinking veal calves is described. Two calves that were persistent ruminal drinkers were used as controls. In addition to clinical parameters, the morphological features of proximal jejunum biopsies were used to monitor the effect of therapy. Ruminal drinking calves showed various degrees of hyperplastic villus atrophy. When the reticular groove reflex was restored, clinical recovery was observed within 10 days; the length of villi increased as well as the villus/crypt ratio at the end of the reconditioning period. Crypt depth, however, did not alter, and the mitosis index significantly decreased. Villus atrophy in the controls gradually worsened. While the calves gained weight after recovery, retarded growth from the ruminal drinking period was not compensated.