Endogenous enzymes in poultry are specific for α-linked carbohydrates similar to that in starch, but they are not active against SBM oligosaccharides because the α-galactosides cannot be hydrolysed due to the lack of α-1,6galactosidase activity in the intestinal mucosa. Consequently, undigested oligosaccharides pass to the distal end of the intestine where they are fermented by gut micro flora to volatile fatty acids (VFA) and gases, thus yielding less energy and creating digestive disturbances. Raffinose and stachyose significantly reduced TMEn values of adult Leghorn roosters when added to the feed at levels equal to that normally found in SBM. Dry matter digestibility also appears to be negatively affected thus, decreasing significantly as stachyose levels increase.