Effects of vitamin E and selenium on some rumen parameters in lambs.

The effects of supplemented selenium and vitamin E on a number of rumen parameters such as the population of rumen protozoa, pH, concentration of volatile fatty acids and ammonia nitrogen in the rumen content were studied. Eight lambs were randomly allocated into two groups: a control group and an experimental group receiving vitamin E (DL-alpha-tocopheryl acetate, 250 mg/kg of feed) and selenium (sodium selenite, 0.3 mg/kg of feed) supplementation. Samples of rumen content were taken from all lambs three times daily once a week (before feeding as well as 3 and 6 h after feeding) over a period of 10 consecutive weeks. In addition, the lambs were weighed at the end of experiment. The total counts and percentage proportions of rumen protozoa, the pH value, and the levels of ammonia nitrogen and volatile fatty acids were determined in the samples of rumen content. The levels of acetic acid, propionic acid, butyric acid and total volatile fatty acids, the total counts of protozoa, and the percentage proportion of Diplodinium were found to be significantly higher in the supplemented than in the control group (P < 0.05, P < 0.01), whereas the pH values and the percentage proportion of Dasytricha ruminantium were significantly lower in the supplemented group than in the control (P < 0.05). However, there was no statistically significant difference between the two groups in ammonia nitrogen levels. The body mass gain of lambs in the supplemented group was significantly higher than that of the control animals (P < 0.01). Combined selenium and vitamin E supplementation of the lambs' ration caused an increase in the levels of volatile fatty acids, total counts of protozoa, and body mass gain while decreasing the pH value of the rumen content.