This experiment was conducted to determine nitrogen fractions and ruminal dry matter and protein degradability of raw or heated (roasted or extruded) soybean seed. Samples were incubated for 2, 4, 8, 16, 24 and 48 h in the rumen of 4 cannulated Kurdish male lambs (50 ± 3 kg BW) . N itrogen fractions of samples were measured by chemical methods. Results showed that extruding decreased non-prot...