Alimentary, blood and other changes due to feeding MnSO4, MgSO4 and Na2SO4

Rats were fed a basal diet or diets containing extra MnSO 4 , MgSO 4 or Na 2 SO 4 in three experiments. The major effects occurred in the experiment with the highest level of extra sulfates (138 mmoles/kg of feed) as follows. The MgSO 4 -fed rats ate less feed than the Na 2 SO 4 -fed rats. Also, in the MgSO 4 group the activity of serum alkaline phosphatase was greater and the cleaned, dried cecum was considerably heavier than in the other groups, and the colon plus rectum was slightly longer than in the basal and MnSO 4 groups. The MnSO 4 -fed rats, compared to rats of the other groups in this experiment, ate less feed, gained less body weight, required more feed per gram of gain, drank more water, voided more urine, showed depigmentation of the labial surfaces of the incisor teeth, had less hemoglobin and serum inorganic phosphorus, and had cleaned, dried stomachs of lighter absolute weight. The erythrocyte count was higher in the MnSO 4 group than in the basal or Na 2 SO 4 groups.