APPARENT DIGESTIBILITIES OF ENERGY, CELL-WALL CONSTITUENTS, CRUDE PROTEIN AND AMINO-ACIDS OF CHINESE OIL SEED MEALS FOR GROWING PIGS

The apparent ileal and faecal digestibilities of energy, crude protein (CP), amino acid and cell wall constituents in feedstuffs of peanut m eal (PNM), soyabean meal (SBM), rapeseed meal (RSM-1), ammoniated rape seed meal (RSM-2), partly dehulled cotton seed meal (CSM) and rice bra n cake (RBC) were determined for non-cannulated pigs (n = 6) or pigs ( n = 6) fitted with ileo-caecal reentrant cannulae. The pigs were fed w ith a cornstarch-based diet formulated to contain about 14% protein. T he results showed that the ileal digestibility of energy was not signi ficantly different between SBM (76.2%) and PNM (74.4%), but that it wa s significantly lower for RBC (P<0.05) than for SBM and PNM. However, the ileal digestibility of energy was significantly lower for RSM-2, R SM-1 and CSM than for RBC. The ileal digestibility of CP was significa ntly higher for PNM (87.3%) than for SBM, and was significantly higher for SBM than for RBC (73.4%) and CSM (73.0%). Although the ileal dige stibility of CP was significantly higher for RSM-2 than for RSM-1, it was significantly lower for RSM-2 than for CSM and RBC. CSM had the lo west ileal digestibilities of lysine (43%), methionine (64%) and threo nine (67%), which are the most important amino acids in amino nutritio n. The ileal digestibility of lysine was highest for SBM (P<0.05), but that of methionine was highest (P<0.05) for RSM-2. PNM, SBM and RSM-2 had a similar ileal digestibility of threonine. PNM contained not onl y the highest amount of arginine (76.6 g kg-1 DM), but also had the hi ghest ileal digestibility of arginine (92%). In general, the faecal an alysis method overestimated the digestibility value of nutrients. The modifying action of the bacteria in the large intestine is irregular, therefore a precise determination of the apparent digestibilities of n utrients, especially the amino acids, cannot be obtained from the faec al analysis method. In contrast to previous findings, a high ileal dig estibility of cell wall constituents was found for oil seed meal.