The nutritive value of barley-derived distillers dried grains (BDDG) and distillers dried grains with solubles (BDDGS) was assessed in digestibility and in sacco rumen degradability experiments. The crude protein contents of BDDG and BDDGS were 26.4 % and 29.9 %, and the crude fibre contents 19.9 % and 17.4 % in DM, respectively. The ADF and NDF contents averaged 33 % and 67 % and the lignin 7.6 % of DM. The digestibilities of the nutrients were measured with four rams in both trials and the distillers by-products were given at two levels, 33 % and 66 %, in hay-based rations. The digestibilities in BDDG and BDDGS were, respectively, 43.1 % and 47.7 % for organic matter, 64.5 % and 66.5 % for crude protein, and 86.7 % and 87.9 % for ether extract. Due to the low digestibilities, the energy values of the two products were low, 0.58 FU/kg DM and 8.0 MJ/kg for both, and DCP/FU 295g for BDDG and 347 g for BDDGS. The rumen degradability of the crude protein of BDDG and BDDGS was found to be low and significantly lower than the degradability of wheat distillery by-products (P < 0.05). Fine grinding gave more rapid degradability. Due to the low total digestibility and reduced lysine content, BDDG and BDDGS may have limited protein availability when given as supplements
