The aim of this study was to evaluate the effects of replacing ground corn with crude glycerin and soybean meal by cottonseed cake, in association or not, on digestibility and intake of dietary nutrients, performance, carcass characteristics and meat quality of feedlot lambs. Thirty-two non-castrated crossbred 1/2 Santa Inês x 1/2 Dorper lambs, with an average body weight of 18.52 ± 3.24 kg (mean ± standard deviation) and with 3 months of age were distributed in a randomized complete block design, into four treatments and eight replicates per treatment, in a 2 × 2 factorial scheme. Four experimental diets were tested with different sources or combinations of energy and protein ingredients, respectively, in the concentrate: 1) ground corn + soybean meal; 2) ground corn and cottonseed cake; 3) crude glycerin and soybean meal; 4) crude glycerin and cottonseed cake. There was an interaction between the energy and protein sources in ether extract intake and total digestible nutrients digestibility (P < 0.01). There was an interaction between the energy and protein sources in the total weight gain (P = 0.03), hot (P = 0.03) and cold (P = 0.04) carcass weights, and shear force (P = 0.29). The inclusion of crude glycerin decreased (P = 0.01) the dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), and non-fibrous carbohydrates (NFC) intakes, and the apparent digestibilitis of OM, NDF, and NFC (P < 0.05). Crude glycerin decreased the amount of retained nitrogen (P = 0.02), lower final weight (P < 0.01), average daily gain and cold carcass yield. An increase ocurred in the NDF intake (P < 0.05) when lambs were fed diet with cottonseed cake and a decrease (P < 0.01) in the digestibilities of DM, OM, CP and NDF. The replacement of 100% of ground corn by crude glycerin, with low purity, is not recommended in diets for feedlot lambs, because it decreases animal performance. In contrast, the total replacement of soybean meal by cottonseed cake can be used in diet for lambs, without causing damage to the performance and meat quality.

本研究的目的是评估用粗甘油和豆粕代替玉米粉与棉籽饼联合或不联合对饲养羔羊的消化率和日粮营养摄入、性能、胴体特征和肉质的影响。32 只非阉割杂交 1/2 Santa Inês x 1/2 Dorper 羔羊，平均体重为 18.52 ± 3.24 kg（平均值 ± 标准差），3 个月大，分布在随机完整区组设计中，分成 4 个处理，每个处理 8 个重复，采用 2 × 2 因子方案。在浓缩物中分别用不同来源或能量和蛋白质成分的组合测试了四种实验日粮：1) 磨碎的玉米 + 豆粕；2) 磨碎的玉米和棉籽饼；3）粗甘油和豆粕；4）粗甘油和棉籽饼。乙醚提取物中的能量和蛋白质来源与总可消化营养素的消化率之间存在相互作用（P < 0.01)。在总增重 ( P  = 0.03)、热 ( P  = 0.03) 和冷 ( P  = 0.04) 胴体重量以及剪切力 ( P  = 0.29) 中，能量和蛋白质来源之间存在相互作用。粗甘油的加入降低了（P  = 0.01）干物质（DM）、有机物质（OM）、粗蛋白（CP）、中性洗涤纤维（NDF）和非纤维碳水化合物（NFC）的摄入量，以及表观OM、NDF 和 NFC 的消化性炎 ( P < 0.05)。粗甘油降低了保留氮的量（P  = 0.02），降低了最终重量（P< 0.01)，平均日增重和冷屠体产量。当羔羊饲喂棉籽饼日粮时，NDF 摄入量增加（P < 0.05），DM、OM、CP 和 NDF 的消化率降低（P < 0.01）。不建议在饲养场羔羊的日粮中用低纯度粗甘油代替 100% 磨碎的玉米，因为这会降低动物的生产性能。相比之下，棉籽饼完全替代豆粕可用于羔羊的日粮，不会对性能和肉质造成损害。