Preintestinal Disappearance of Vitamin E in Ruminants

Steers and ewes were used to evaluate the influence of the preintestinal tract of ruminants on vitamin E. In the first experiment, vitamin E, chromic oxide and polyethylene glycol were administered to steers fitted with permanent abomasal fistulas and fed balanced corn, alfalfa hay and soybean meal diets containing 20, 40, 60 and 80% corn in ascending, then descending, order. Disappearance was estimated by using weighted averages of ratios of vitamin E to chromic oxide and polyethylene glycol in abomasal contents with ratios administered in gelatin capsules 24 hours earlier. Preintestinal disappearance of vitamin E averaged 8.4, 22.2, 25.0 and 42.4% for the diets containing 20, 40, 60 and 80% corn, respectively. Treatment effects were significant (P < 0.01), while period effect was not. Except for the differences between the 40% and 60% diets, all differences between individual diets were significant (P < 0.02). In the second experiment, blood samples from controls and from ewes whose digestive tracts were ligated at the pylorus were taken at 0, 2, 4, 8, 12 and 24 hours after the ewes received 5000 IU vitamin E in a bolus and analyzed for vitamin E. The results did not suggest appreciable preintestinal absorption of vitamin E. It was concluded that the preintestinal tract of ruminants exerts a major influence on vitamin E utilization.