This experiment was conducted to investigate the effects of feeding different silages on the performance of fattening lambs and nutrients digestibility. Sixteen uniform males of Awassi lambs were used in feeding trial that was lasted for 77 days. The trial was followed by a digestion trial. Lambs were divided into four experimental groups during the trial and had free access to water. Three types of silage were prepared using wheat straw (WS), olive cake (OC) and citrus pulp (CP). The three by-products were mixed in the following ratios for silage 1 (60:27:13), for silage 2 (20:54:26) and for silage 3 (0:48:52), respectively. The forages were offered to lambs along with fixed amount of a commercial fattening concentrate which was 78% of total rations fed on air dry basis. Silage type had no effect on lambs weight development and lambs average daily gain. The feed conversion efficiency was the highest (P.05) in lambs fed the silage 1. However, the cot of gain was the lowest (P.05) in lambs fed the silage 3. Values of nutrient digestibility increase (P0.05) for all types of silages, especially when wheat straw was excluded frm the rations. The results of this study indicate that silages of wheat straw, olive cake and citrus pulp can be used for lambs in fattening operations.