EXAMINATION OF THE INFLUENCE OF FOOD-WITH DRAWAL ON BEHAVIOR, BLOOD-PARAMETERS AND WEIGHT OF THE INTESTINE

In 3 ponies (114-173 kg) feed was withdrawn for 100 hours after the po nies were fed corn-silage. Blood samples were taken every 4 hours duri ng the withdrawal-time and evaluated for certain parameters. The weigh t of the intestine and the chyme-contents were controled after euthana sia. 3 other ponies (135-203 kg) were checked upon the same parameters as a control-group. Main results are as follows: 1) The ponies stayed clinically unconspicuous during the withdrawal-time. 2) During the wi thdrawal-time the packed cell volume (PCV) decreased (with no changes in total protein) and both, blood glucose and pH decreased as well. A leukopenia and a moderate increase of AST and SDH were detected, while tryglycerids and bilirubin highly increased. The plasma-calcium and - magnesium levels were constant, but the plasma levels of anorganic pho sphat increased. 3) The post mortem examination revealed the tendency of a weight increase of the intestine and of the liver (approx. 10%), a decrease of the amount of dry-matter within the chyme, though the am ount of water was constant. (Significant reduction of dry-matter withi n the chyme, except within the colon descendens).The findings were dis cussed in context with the pathogenisis of the so called typhlo-coliti s.