Two experiments were used to evaluate the effects of using cotton gin trash (CGT) treated with urea and exogenous fibrolytic enzymes (EFE) on feed chemical composition, in vitro dry matter digestibility and gas production (Trial 1), and apparent in vivo digestibility, intake and growth performance of feedlot Santa Ines lambs (Trial 2). The Trial 1 used a completely randomized 2×4 factorial design with four replications of treating CGT with urea (0 and 6%) and EFE (0, 2, 4, 6 g/kg; 75% cellulase, 25% hemicellulase). The Trial 2 used a complete randomized design with 8 replications to evaluate the use of CGT treated with 6% urea and one of four EFE concentrations (0, 2, 4, 6 g/kg) in 50% concentrate and 50% CGT diets; the control diet contained untreated CGT. In Trial 1, there was interaction between urea and EFE dose for DM, EE, ADF, TN, and fractions A and C of nitrogen (P < 0.001). Urea reduced all cell wall components (P < 0.05) except for hemicellulose (P > 0.05). Increasing EFE resulted in a linear decrease of NDF, ADF, cellulose, hemicellulose, and lignin. Both urea and EFE increased (P < 0.05) IVDMD. There was an interaction (P < 0.001) between urea and EFE for TN and nitrogen fractions A and C. Independently of EFE dose, urea affected all carbohydrate fractions. Increasing EFE linearly increased (P < 0.001) NFC and decreased (P < 0.008) fractions B2 and C. An EFE vs. urea interaction (P < 0.02) affected L, CGP, BIO and TDOM. The CGT pre-treated with urea and 2 g/kg of EFE generated the greatest total gas production but urea without EFE resulted in the least gas production. In Trial 2, increasing EFE linearly increased DM and OM intakes and quadratically NFC intake; as well as linearly increased (P < 0.002) DM, OM and NFC digestibilities. However, fiber apparent digestibility (ADF and FC) was negatively affected by EFE (P < 0.05). Final BW, BW gain and ADG linearly increased with EFE dose (P < 0.02). Combining urea and EFE was efficient in reducing structural cell wall components and improving the in vitro digestibility and gas production of CGT. The EFE improved OM, fiber and NFC digestibility and DM, OM and NFC intake that supported greater growth performance of feedlot sheep.

进行了两个实验，以评估使用尿素和外源性纤溶酶（EFE）处理的轧花轧棉垃圾（CGT）对饲料化学成分，体外干物质消化率和产气量（试验1）以及明显的体内消化率的影响，饲养场Santa Ines羔羊的摄食量和生长性能（试验2）。试验1使用完全随机的2×4析因设计，重复四次，分别用尿素（0和6％）和EFE（0、2、4、6 g / kg； 75％纤维素酶，25％半纤维素酶）处理CGT。试验2使用了完整的随机设计，进行了8次重复，以评估在6％的尿素和50％的CGT日粮中使用6％尿素和四种EFE浓度（0、2、4、6 g / kg）之一处理的CGT的使用。对照饮食中含有未经处理的CGT。在试验1中，DM，EE，ADF，TN，P <0.001）。尿素减少了除半纤维素（P > 0.05）外的所有细胞壁成分（P < 0.05）。EFE的增加导致NDF，ADF，纤维素，半纤维素和木质素的线性下降。尿素和EFE均增加（P <0.05）IVDMD。尿素和EFE之间对于TN和氮组分A和C有相互作用（P <0.001）。与EFE剂量无关，尿素影响所有碳水化合物组分。EFE的增加线性增加（P <0.001）NFC并降低（P <0.008）馏分B2和C。EFE与尿素的相互作用（P<0.02）会影响L，CGP，BIO和TDOM。用尿素和2 g / kg的EFE预处理的CGT产生的总气体产量最高，但不含EFE的尿素的气体产量最低。在试验2中，增加EFE会线性增加DM和OM的摄入量，并增加NFC的摄入量；以及线性增加（P <0.002）DM，OM和NFC可消化性。但是，纤维的表观消化率（ADF和FC）受到EFE的负面影响（P <0.05）。最终BW，BW增益和ADG随着EFE剂量线性增加（P<0.02）。尿素和EFE的组合可有效减少细胞壁的结构成分，并提高CGT的体外消化率和产气量。EFE改善了OM，纤维和NFC的消化率，以及DM，OM和NFC的摄入量，从而提高了饲养场绵羊的生长性能。