The effects of oatmeal and various fractions from a hard white and hard red winter wheat on rat weight gains and fecal loss of protein, ash, calcium, and zinc were compared. Oatmeal diets produced weight gains similar to those of the whole wheat flour diets. No significant differences occurred in weight gains between animals fed diets containing whole flour, straight-grade flour, or bran of the hard white wheat and those fed respective hard red winter wheat diets. Although caloric contents of the wheat bran diets were lower than those of the other diets and bran-fed rats lost more protein and ash in feces, animals fed the bran diets gained as much weight as those fed straight-grade flour diets. Feed intake was highest in bran-fed animals, and the bran diets were the least efficient feeds. Animals fed bran diets had the highest wet and dry fecal weight and highest fecal water-holding capacity; no differences occurred between the hard white and hard red winter bran diets. Fecal water-holding capacity was strongly correlated with total dietary fiber (r = 0.9738, P = 0.0001). Animals fed oatmeal lost the least amount of calcium per day, had the lowest percent loss of calcium, and absorbed more calcium than those fed red or white wheat diets or the control diet, which contained cellulose. Greatest daily loss of zinc occurred with the wheat bran diets, but zinc concentration and daily amounts of zinc absorbed also were highest with those diets. More zinc was absorbed per day from the oatmeal diet than from all other diets, except those containing wheat brans. An inverse relationship was observed between percent calcium loss and soluble dietary fiber (r = -0.4996, P = 0.003), whereas no significant correlation occurred between insoluble and total dietary fiber or phytic acid and percent calcium loss. However, significant correlations were observed between the daily amount of zinc in feces and insoluble dietary fiber (r = 0.8709, P = 0.0001), total dietary fiber (r = 0.9137, P = 0.0001), and phytic acid (r = 0.9552, P = 0.0001). The amounts of calcium and zinc absorbed daily were strongly correlated with intakes (r = 0.9124, P = 0.0001 and r = 0.9134, P = 0.0001, respectively). | |
