AMINO ACID DIGESTIBILITY AS AFFECTED BY VARIOUS FIBER SOURCES AND LEVELS 1. DIFFERENCE BETWEEN ILEAL AND FECAL DIGESTIBILITY OF AMINO ACIDS

A simple cross-over design was used in digestion experiment carried out on finishing pig (70 kg body wt.) fitted with ileal T-cannula, to determine the difference between ileal and fecal digestible values as affected by various fiber sources and levels. The series of semi-purified diets were formulated in an attempt to meet 1, 3, 7 and 9% crude fiber level, with alfalfa meal (AFM), rubber seed meal (RSM), leucaena meal (LM) and cellulose. Both the levels and sources influenced the amino acid digestibilities, as increasing crude fiber level the digestibilities increased. The digestibilities of amino acids at ileal level were higher than at fecal level. The magnitude of response were ranged from 1.76 to 8.41 percentage unit or 4.86 by average. The dry matter digestibilities of the diets reflect the digestibilities of amino acids as accumulation of fiber would increase endogenous losses. It indicates that the digestibilities of amino acids varied irregularly among diets, probably depended on a dietary nutrient and individual fiber fraction contents.