Dietary Fiber and Fecal Characteristics in Rats: Effects of Level and Particle Size of Bran

Particle size and levels of dietary wheat brans were compared in regard to their effects on various fecal characteristics in rats. Particle size appeared to have no effect on fecal moisture. When compared with a 15% medium bran diet, a 15% fine bran diet decreased wet weight (−9%, P < 0.01) and volume (−18%, P < 0.01), and increased density (+14%, P < 0.01) of feces. A 15% coarse bran diet induced a low fecal density (0.839), which is a desirable effect. Density decreased when the level of bran of the same particle size was increased. However, a 25% fine bran diet still induced higher (P < 0.05) density than a 15% coarse bran diet, stressing the importance of bran coarseness on fecal density.