Rusche Warren C, Walker Julie Ann, Sexton Peter, Brattain Rebecca S, Smith Zachary K
Department of Animal Science, South Dakota State University, Brookings, SD.
Department of Agronomy, Horticulture and Plant Science, South Dakota State University, Brookings, SD.
Transl Anim Sci. 2020 Sep 12;4(3):txaa173. doi: 10.1093/tas/txaa173. eCollection 2020 Jul.
Crossbred beef steers with a high percentage of Angus ancestry [ = 240, initial shrunk body weight (BW), 404 ± 18.5 kg] were used in a 117-d feedlot experiment to evaluate the effect of hybrid rye (Rye; KWS Cereals USA, LLC, Champaign, IL) as a replacement for dry-rolled corn (DRC) on growth performance, carcass traits, and comparative net energy (NE) value in diets fed to finishing steers. Rye from a single hybrid (KWS Bono) with an ergot alkaloid concentration of 392 ppb was processed with a roller mill to a processing index (PI) of 78.8 ± 2.29. Four treatments were used in a completely randomized design ( = 6 pens/treatment; 10 steers/pen), where DRC (PI = 86.9 ± 4.19) was replaced by varying proportions of Rye [DRC:Rye, dry matter (DM) basis (60:0), (40:20), (20:40), and (0:60)]. Liver abscess scores and carcass characteristics were collected at the abattoir. Carcass-adjusted performance was calculated from hot carcass weight (HCW)/0.625. Performance-adjusted NE was calculated using carcass-adjusted average daily gain (ADG), DM intake (DMI), and mean equivalent shrunk BW with the comparative NE values for rye calculated using the replacement technique. Data were analyzed using the GLIMMIX procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC) with pen as the experimental unit. Treatment effects were tested using linear and quadratic contrasts, as well as between diets with and without Rye. Replacing DRC with Rye linearly decreased ( ≤ 0.01) carcass-adjusted final BW, ADG, DMI, and gain:feed (G:F). Feeding rye linearly decreased HCW and longissimus muscle area ( ≤ 0.04). Distributions of liver scores and USDA grades for quality and yield were unaffected by treatment ( ≥ 0.09). Estimated replacement NE for maintenance (NEm) and gain (NEg) values for rye, when included at 60% of diet DM, were 1.90 and 1.25 Mcal/kg, respectively. Rye can be a suitable feed ingredient in finishing diets for feedlot steers. Estimated replacement values of Rye when fed at 60% of diet DM closely agreed with current tabular standards but, when included at 20% of diet DM, estimated NEm and NEg values of Rye were increased 9.5% and 12.8%, respectively. Net energy value of Rye for gain is approximately 84% compared to DRC; thus, the complete replacement of DRC with Rye depressed DMI, ADG, G:F, and carcass weight.
具有高比例安格斯血统的杂交肉牛（初始缩体体重（BW）= 240，404 ± 18.5千克）被用于一项为期117天的饲养场试验，以评估杂交黑麦（黑麦；KWS谷物美国有限责任公司，伊利诺伊州尚佩恩）替代干碾压玉米（DRC）对育肥牛生长性能、胴体性状和日粮比较净能（NE）值的影响。来自单一杂交品种（KWS Bono）、麦角生物碱浓度为392 ppb的黑麦，用辊磨机加工至加工指数（PI）为78.8 ± 2.29。试验采用完全随机设计的四种处理方式（每个处理6个围栏；每围栏10头牛），其中用不同比例的黑麦替代DRC（DRC：黑麦，干物质（DM）基础比例为（60:0）、（40:20）、（20:40）和（0:60））。在屠宰场收集肝脏脓肿评分和胴体特征。胴体调整性能根据热胴体重（HCW）/0.625计算。性能调整后的NE使用胴体调整后的平均日增重（ADG）、DM摄入量（DMI）和平均等效缩体BW，并采用替代技术计算黑麦的比较NE值。数据使用SAS 9.4的GLIMMIX程序（SAS公司，北卡罗来纳州卡里）进行分析，以围栏作为试验单位。使用线性和二次对比以及含和不含黑麦的日粮之间进行处理效应测试。用黑麦替代DRC线性降低了（P≤0.01）胴体调整后的最终BW、ADG、DMI和增重：饲料比（G:F）。饲喂黑麦线性降低了HCW和背最长肌面积（P≤0.04）。处理对肝脏评分分布以及美国农业部质量和产量等级没有影响（P≥0.09）。当黑麦占日粮DM的60%时，其维持净能（NEm）和增重净能（NEg）的估计替代值分别为1.90和1.25 Mcal/kg。黑麦可以是育肥牛育肥日粮中的合适饲料成分。当黑麦占日粮DM的60%时，其估计替代值与当前表格标准非常接近，但当占日粮DM的20%时，黑麦NEm和NEg的估计值分别提高了9.5%和12.8%。与DRC相比，黑麦的增重净能值约为84%；因此，用黑麦完全替代DRC会降低DMI、ADG、G:F和胴体重。
