METABOLIC PARAMETERS AFFECTED BY FEEDING VARIOUS TYPES OF FIBER TO GUINEA-PIGS

Replicate experiments (2) using young guinea pigs were designed to study the effects of various dietary fibers on growth, digestion, and metabolite levels. Trial 1 was carried out using 4 fiber sources (cellulose A, hydrolyzed cellulose A, cellulose S and alfalfa). Growth rate, cellulose digestion and serum and liver cholesterol concentrations were measured. Trial 2 was a replicate of trial 1; serum nitrogeneous components, serum mineral levels, serum glucose and 4 serum enzyme levels were also measured. Guinea pigs fed alfalfa exhibited higher growth responses when compared to those obtained with guinea pigs fed the other sources of fiber while cellulose digestion by these guinea pigs was decreased. Serum cholesterol concentration was increased by feeding hydrolyzed cellulose A but no differences between treatments were noted in liver cholesterol concentration. Serum nitrogeneous components were not affected by fiber source nor was the concentration of serum glucose. Serum P levels were elevated with cellulose S and alfalfa feeding but no difference in Ca levels was detected. Alkaline phosphatase (AP) activity was stimulated when alfalfa served as the source of fiber, as was serum glutamic-pyruvate transaminase (SGPT) and lactic dehydrogenase (LDH). SGPT activity was also elevated with purified wood cellulose S feeding, and LDH activity was higher for all treatments compared with cellulose A. No differences between treatments were noted in creatinine phosphokinase (CPK) activity. No differences in the apparent digestibilities of Ca and Mg were noted between treatments. Those guinea pigs fed alfalfa exhibited a significantly lower apparent digestibility of P when compared with those fed the other fiber sources.