Intraruminal administration of milk in the calf as a model for ruminal drinking: morphological and enzymatical changes in the jejunal mucosa.

In order to develop a calf model for studying the syndrome of ruminal drinking (RD) in veal calves, three dual-fistulated calves were used to test the effect of intraruminal administration of milk replacer on the jejunal mucosa. Biopsies of the proximal jejunal mucosa were taken through a jejunal fistula and the mucosal morphology and the activities of two brush border enzymes, lactase and alkaline phosphatase, were determined. Means of villus length and brush border enzyme activities decreased during the period of intraruminal administration of milk. The hyperplastic villus atrophy in this model was similar to that found in chronic RD patients in previous studies. This could not be associated with isolation of pathogenic micro-organisms from the faeces and is probably the consequence of the intraruminal milk feeding procedure itself. Clinical recovery from the signs of RD occurred rapidly after intraruminal administration of milk ceased and was followed by restoration of villus length and brush border enzyme activities 3-4 weeks later.

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.

Consequences of failure of the reticular groove reflex in veal calves fed milk replacer.

A number of problems seen in veal calves are associated with insufficient adaptation to the changes in husbandry connected with the fattening system. These problems include chronic tympanitis, chronic vomiting, cachexia, unthriftiness, abomasal erosions and ulcers. Some of these problems are associated with failure of the reticular groove reflex, and result in ruminal drinking. Persistent ruminal drinking causes a syndrome characterised by a variety of symptoms such as unthriftiness, severe growth retardation, inappetence, recurrent tympany, abdominal distension, a long dry haircoat and clay-like faeces. Clinical studies performed to investigate the pathogenesis of the syndrome are described. It was found that the milk was stored in the rumen and was partly broken down. The presence of milk in the rumen induced typical changes in the ruminal mucosa (hyper/parakeratosis) and also inhibited casein clot formation in the abdomasum. The small intestinal mucosa showed villous atrophy. After training, the reticular groove reflex was re-established in a number of patients but the growth rate of these calves did not return to normal.

[A form of dermatosparaxis in a Texel lamb]. / Een vorm van dermatosparaxis bij een Texelaar.

A case of dermatosparaxis in a Texel lamb is reported in the present paper. The most striking clinical symptom consisted in the formation of multiple seromas. The findings and symptoms in this case showed a marked similarity to those reported in the literature, though they were not identical.