Nine male goats and nine castrated lambs were randomly divided into three groups of six animals to receive one of three experimental diets in a digestion trial. Diet S, provided chopped sorghum straw (SS), 28/ concentrate (C) and 10/ Dolichos lablab hay (D). Diet Su1 provided SS containing 2/ urea, 24/ C and 12/ D, and diet Sue1 provided SS treated to contain 2/ urea and ensiled for 28 days, plus 25/ C and 14/ D. Twenty four lambs were randomly divided into three groups of eight animals to receive one of three diets in a 56-day growth trial; diet S2 provided SS plus 60/ C; diet Su2 provided SS containing 2/ urea plus 60/ C, and diet Sue2 provided SS treated to contain 2/ urea and ensiled for 28 days, plus 60/ C. The digestion trial showed higher (P<.05) daily intake of dry matter, organic matter, crude protein and neutral detergent fiber for S, than for Sue1 and Su1. Dry matter intake was 55.93; 39.42 and 42.34 g[kgE0.75)E-1) for S1, Su1 and Sue1, respectively. Dry matter intake was slightly higher for lambs [50 g[kgE0.75)E-1] than for goats [42 g[kE0.75)E-1]. There was no effect of dietary treatments on apparent nutrient digestibility. During the growth trial, intake of straw varied from 17.97 (S2) to 24.78 g[kgE0.75)E-1 (Sue2), but differences were not significant. Daily gain did not differ between treatments. Total feed intake and feed efficiency were only slightly affected by dietary treatments. Average feed intake was 4.36/ of body weight. High concentrate intakes may have upset the effect of urea treatment and silo fermentation in this study
