The objective of this study was to evaluate the performance, feeding behavior, carcass traits, and meat quality of feedlot lambs using 2 types of silage, sorghum or soybean. Twenty-eight male non-castrated market lambs weighting 20 ± 2 kg were used. Diets were formulated to be isonitrogenous and isocaloric. The animals were slaughtered after 50 days of experiment, with 32.13 ± 5.09 kg of body weight. Lambs fed with soybean silage showed increased time for feed intake (P = 0.01). There was no difference for allowed daily gain, dry matter intake, feed conversion, and carcass traits between diets. Meat from lambs fed with soybean silage showed decreased shear force (P = 0.001) compared to sorghum silage, with no differences (P > 0.05) for chemical composition, color, and cooking loss. The intake of sorghum silage increased (P < 0.05) C6:0, C16:0, C20:0, C14:1, and C16:1 fatty acids content of Longissimus lumborum intramuscular fat. The intake of soybean silage showed an increased (P < 0.05) content of C18:1ω9t, C18:2ω6c, and sum of ω6 fatty acids. The feed cost and profit from the use of sorghum and soybean silage were US$ 0.