The aim of this study was to evaluate the effect of substitution of Cynodon hay with banana plantation residue hay on the carcass characteristics and tissue composition of commercial cuts of feedlot Santa Inês lambs. Twenty-five whole lambs were used, with an average age of five months and an initial live weight of 26.95 kg (± 1.5), distributed in a completely randomized design with five treatments (1 = 40% Cynodon spp. hay + 60% concentrate; 2 = 20% banana leaf hay + 20% Cynodon spp. hay + 60% concentrate; 3 = 40% banana leaf hay + 60% concentrate; 4 = 20% banana pseudostem hay + 20% Cynodon spp. hay + 60% concentrate; 5 = 40% banana pseudostem hay + 60% concentrate) and five repetitions. The lambs were slaughtered on day 69 of the experiment. The variables evaluated were: live weight without fasting (LWWF), live weight post-fasting (LWPF), morphometric measurements in vivo and postmortem, hot and cold carcass weights (HCW, CCW), hot and cold carcass yield (HCY, CCY), biological performance and weight loss by chilling. The carcasses were divided into eight commercial cuts: neck, shoulder, foreshank and hindshank, breast and flank, loin, leg and rack. The leg, shoulder and loin were dissected into muscle, fat and bone. The animals fed on pseudostem hay showed higher LWWF, LWPF, body length, HCW and CCW; however, the HCY, CCY, morphometric measurements and commercial cut weights and yields were not altered by the treatments. The use of pseudostem hay allows for heavier carcasses; however, the use of coproducts changed the characteristics and carcass yield of the assessed commercial cuts. cinco meses, peso vivo inicial de 26,95 kg (± 1,5), distribuídos em delineamento inteiramente casualizado com cinco tratamentos (1= 40% de feno Cynodon spp. + 60% concentrado, 2= 20% de feno de folha de bananeira e 20% de feno de Cynodon spp. + 60% concentrado, 3= 40% de feno de folha de bananeira + 60% concentrado, 4= 20% de feno de pseudocaule de bananeira e 20% de feno de Cynodon spp. + 60% concentrado, 5= 40% de feno de pseudocaule de bananeira + 60% concentrado) e cinco repetições. Os cordeiros foram abatidos aos 69 dias de experimentação. As variáveis avaliadas foram: peso vivo sem jejum (PVSJ), peso vivo com jejum (PVCJ), medidas morfométricas in vivo e da carcaça, peso da carcaça quente e fria (PCQ, PCF), rendimento da carcaça quente e fria (RCQ, RCF), rendimento biológico e perda por resfriamento. As carcaças foram divididas em oito cortes comerciais, sendo o pernil, paleta e lombos dissecados em músculo, gordura e osso. Os animais alimentados com feno de pseudocaule apresentaram maior PVSJ, PVCJ, comprimento corporal, PCQ, PCF, entretanto, o RCQ, RCF, medidas morfométricas da carcaça, pesos e rendimentos dos cortes comerciais não foram alterados pelos tratamentos. O uso do feno de pseudocaule permite a obtenção de carcaças mais pesadas, entretanto, os coprodutos alteram as características e rendimento da carcaça e dos cortes comerciais avaliados.