A SIMPLE METHOD FOR ESTIMATION OF NEUTRAL DETERGENT-SOLUBLE FIBER

A method was developed to estimate the neutral detergent-soluble fibre (NDSF) content of feeds. Citrus pulp, sugar beet pulp, soybean hulls, separated leaves and stems from mature and immature alfalfa, red clov er, reed canarygrass and timothy were analysed. Half-gram samples were stirred at room temperature for 4 h with 100 ml of 90:10 (v/v) ethano l/water to extract low molecular weight substances, crude protein (CP) and ash to produce ethanol-insoluble residues (EIR). Sampies were ref luxed for Ih with neutral detergent solution and heat stable alpha-amy lase to extract low molecular weight substances, NDSF, starch, CP and ash to produce neutral detergent residues (NDF). The EIR and NDF were analysed for organic matter (OM; EIROM; NDFOM) and CP (EIRCP; NDFCP), and EIR was analysed for starch. Values were expressed as proportions of the original sample dry matter. The NDSF was calculated as the diff erence in OM mass between EIR and NDF after correction for CP and star ch by the equation: EIROM - NDFOM - EIRCP + NDFCP - EIR starch. Extrac tions with 90:10 (v/v) ethanol/water gave a higher yield of EIR and ND SF than did 80:20 (v/v) ethanol/water. The method gave good precision and is convenient for assessing NDSF content of feeds.