The substitution of sorghum stover with sugarcane top silage [0 (T1), 5 (T2) and 10% (T3) DM] in high concentrate diets for feedlot hair lambs was evaluated in two experiments. In experiment one, ruminal dry matter degradability (RDMD) was evaluated in three ruminally cannulated 6-month-old Pelibuey sheep in a 3×3 Latin square design. The RDMD was determined by the nylon bag technique at incubation times of 4, 8, 12, 24, 48 and 72h. There was no effect of diet (P>0.05) for the rapidly degraded (a) or degradable fraction (b) of dry matter. The maximum degradability (a+b) was greater for T3 than T1 (P<0.05); T2 was similar to T1 and T3 (P>0.05). Effective degradability at 6% h −1 of ruminal turnover (k) was lower for T2 (P<0.05) than for T1 and T3; ruminal turnover was higher (P>0.05) for T1 than for T3. Growth performance of feedlot hair lambs was evaluated in a second experiment using the same diets as in experiment one. Twenty-seven 5-month-old intact crossbred male hair lambs (19.04±1.56kg) were assigned at random to 9 pens (3 lambs per pen). The feeding trial lasted for 63days. Feed intake decreased (P<0.05) with increasing level of sugarcane tops silage in diet. Nevertheless daily weight gain was not affected by diet. There was no treatment effect (P>0.05) on feed efficiency (gain/feed intake). It is concluded that ensiled sugarcane tops is a practical alternative to substitute for sorghum stover in diets for growing finishing feedlot lambs. Partial replacement of sorghum stover with ensiled sugar tops does not negatively affect daily weight gain.