Podversich Federico, Rusche Warren, Bird Scott, Rops Brad, Sexton Pete, Smith Zachary
Department of Animal Science, South Dakota State University, Brookings, SD 57007, USA.
South Dakota State University Agricultural Experiment Station, Southeast Research Farm, Beresford, SD 57004, USA.
Transl Anim Sci. 2025 May 2;9:txaf059. doi: 10.1093/tas/txaf059. eCollection 2025.
Two experiments were conducted to evaluate the effects of feeding dry-rolled hybrid rye grain (DRRG) as a replacement for dry-rolled corn (DRC) in beef cattle finishing diets. Two inclusion strategies for rye grain (RG) were evaluated: a total replacement of DRC for a limited time and a partial replacement during the entire feeding trial for Exp. 1 and 2, respectively. In Exp. 1, primarily Angus steers [n = 110, initial shrunk body weight (BW) 391 ± 31.5 kg] were blocked by BW and pen location in 7 blocks and assigned to either 1-A) DRC as the sole grain during the entire finishing (DRC), or 1-B) DRRG during the initial 46 d (replacement phase) and then switched to DRC (DRRG/DRC). In Exp. 2, primarily Angus steers (n = 44, initial shrunk BW 436 ± 41.0 kg) were blocked by BW and pen location in 4 blocks and assigned to either 2-A) DRC as the sole grain (DRC), or 2-B) the dietary grain component was a blend of one-third DRRG and two-thirds DRC (DM basis), during the entire feeding trial (MIX). Steers were fed for a total of 144 and 119 d in Exp. 1 and Exp. 2, respectively. Pen was the experimental unit, and data were analyzed as a randomized complete block design for both experiments. In Exp. 1, DRRG-fed steers had 18% less dry matter intake (DMI; = 0.01) and 13% less average daily gain (ADG; = 0.01) during the replacement phase. Cumulatively, steers initially fed with the DRRG-based diet tended to consume less than steers continuously fed the DRC-based diet ( = 0.08). However, cumulative ADG, final body weight (FBW), and hot carcass weight (HCW) did not differ ( ≥ 0.16). Steers fed DRRG tended to have lesser marbling scores and USDA Yield Grades ( = 0.08). In Exp. 2, Steers fed MIX tended to have less DMI expressed as % of BW ( = 0.09); no other differences were observed for growth performance or carcass characteristics. In conclusion, both alternatives serve to include rye in feedlot diets, with minimal effects on cumulative performance. However, in the current experiment total replacement of DRC with DRRG for a portion of the feeding period reduced feed intake, body weight gain, and carcass quality.
进行了两项试验，以评估在肉牛育肥日粮中用干碾压杂交黑麦谷物（DRRG）替代干碾压玉米（DRC）的效果。评估了黑麦谷物（RG）的两种添加策略：在试验1和试验2中，分别在有限时间内完全替代DRC以及在整个饲喂试验期间部分替代。在试验1中，主要是安格斯阉牛（n = 110，初始空腹体重（BW）391 ± 31.5千克）按体重和栏位位置分为7个区组，并分配至以下两组之一：1 - A）在整个育肥期以DRC作为唯一谷物（DRC组），或1 - B）在最初46天（替代期）饲喂DRRG，然后换为DRC（DRRG/DRC组）。在试验2中，主要是安格斯阉牛（n = 44，初始空腹体重436 ± 41.0千克）按体重和栏位位置分为4个区组，并分配至以下两组之一：2 - A）以DRC作为唯一谷物（DRC组），或2 - B）在整个饲喂试验期间日粮谷物成分是三分之一DRRG和三分之二DRC的混合物（以干物质计）（MIX组）。试验1和试验2中阉牛分别总共饲喂144天和119天。栏为试验单位，两个试验的数据均按随机完全区组设计进行分析。在试验1中，在替代期，饲喂DRRG的阉牛干物质摄入量（DMI；P = 0.01）减少18%，平均日增重（ADG；P = 0.01）减少13%。累积来看，最初饲喂基于DRRG日粮的阉牛的采食量往往低于持续饲喂基于DRC日粮的阉牛（P = 0.08）。然而，累积ADG、终体重（FBW）和热胴体重（HCW）并无差异（P≥0.16）。饲喂DRRG的阉牛大理石花纹评分和美国农业部产量等级往往较低（P = 0.08）。在试验2中，饲喂MIX组的阉牛以占体重百分比表示的DMI往往较低（P = 0.09）；在生长性能或胴体特性方面未观察到其他差异。总之，两种替代方法都能在育肥牛日粮中添加黑麦，对累积性能影响最小。然而，在当前试验中，在部分饲喂期用DRRG完全替代DRC会降低采食量、体重增加和胴体品质。
