The effects of some selected purified fibers were compared to those derived from cereals or legume seeds. Rats were fed for at least 9 weeks and measurements were taken to determine feed consumption,
weight gain, feed efficiency ratios (
FER), protein efficiency ratios (PER), apparent
protein digestibility, and rate of transit through the gastrointestinal tract. Most diets were designed to contain approximately 10%
dietary fiber and 10%
protein. Compared to the fiber-free diet,
pectin reduced
weight gain, FER, PER and apparent
protein digestibility values.
Cellulose,
xylan and
raffinose had no influence on feed intake,
weight gains or FERs. However,
cellulose and
xylan increased PER values and the rates of food passage but decreased the apparent
protein digestibility values. Feed utilization,
protein digestibility and growth were similar for the
wheat bran, corn bran and fiber-free diets. These cereal fibers caused the rates of transit to be significantly increased relative to the fiber-free control diet. The hull and cell-wall-fiber fractions of beans, when compared to the fiber-free diet, had little effect on feed consumption, growth, FER or PER. The cell-wall-fiber fraction reduced apparent
protein digestibility and the hull fraction accelerated food passage relative to the fiber-free diet.