Neville Bryan W, Lekatz Leslie A, Moore Rebecca L, Pickinpaugh Wayde J, Kassetas Cierrah J
Carrington Research Extension Center, North Dakota State University, Carrington, ND 58421, USA.
Department of Agriculture and Natural Resources, University of Minnesota Crookston, Crookston, MN 56716, USA.
Transl Anim Sci. 2021 Oct 6;5(4):txab194. doi: 10.1093/tas/txab194. eCollection 2021 Oct.
Two experiments were conducted to evaluate the impacts of bunk management on dry matter intake (DMI), growth performance, carcass characteristic, and hydrogen sulfide (HS) concentrations in beef steers fed modified distillers grains with solubles (MDGS; DM basis). In Experiment 1, 139 steers (440.4 ± 31.0 kg) were randomly assigned to one of 16 pens with pen randomly assigned to one of two treatments: 1) Control (CON, bunks managed to be devoid of feed prior to feeding), or 2) Over-fed (OVF, bunks managed to have minimum of 2.54 cm of feed remaining each morning) during adaptation. Following adaptation all steers in Experiment 1 were transitioned to CON bunks and followed to finishing. In Experiment 2, 126 steers (445.4 ± 40.63 kg) were randomly assigned to one of 16 pens. Treatments in Experiment 2 were arranged in a 2 × 2 factorial and include the two bunk management strategies utilized in Experiment 1 (OVF or CON) and either 25% MDGS or 50% MDGS (DM basis). Ruminal HS was measured via rumenocentesis during dietary adaptation. There were no differences ( ≥ 0.13) observed in either experiment for growth performance due to bunk management. In Experiment 1, OVF steers had greater ( = 0.001) DMI during adaptation; however, overall DMI was not different ( = 0.14) between treatments. In Experiment 2, DMI (d 0 to 104) tended to decrease ( = 0.09) with greater MDGS inclusion. Hot carcass weight, ribeye area, marbling score, and quality grade were not affected ( ≥ 0.48) by either bunk management or MDGS inclusion. In Experiment 2, back fat (1.30 vs. 1.17 ± 0.042 cm) and yield grade (3.2 vs. 3.0 ± 0.11) were greater ( = 0.03) for CON steers compared with OVF but were not affected ( = 0.59) by MDGS inclusion. In Experiment 1, HS tended ( = 0.07) to be greater in steers on OVF compared with CON. In Experiment 2, bunk management strategy did not impact ( = 0.82) HS concentrations. There was a MDGS inclusion × day interaction for HS with steers fed 50% MDGS having greater ( < 0.01) HS concentrations compared with steers fed 25% MDGS on d 28 and 35. Bunk management strategy during adaptation did not impact growth performance but did reduce intake in Experiment 1. Yield grade decreased when OVF bunk management was applied throughout Experiment 2. Response of HS concentrations in the rumen were variable and likely influenced by inconsistencies in bunk management and resulting DMI during the early portions of the feedlot study.
进行了两项试验，以评估牛栏管理对饲喂改性干酒糟及其可溶物（MDGS；干物质基础）的育肥牛干物质采食量（DMI）、生长性能、胴体特性和硫化氢（HS）浓度的影响。在试验1中，139头育肥牛（440.4±31.0千克）被随机分配到16个栏舍中的一个，栏舍被随机分配到两种处理方式之一：1）对照（CON，在饲喂前将牛栏管理为空栏），或2）过度饲喂（OVF，在适应期每天早晨将牛栏管理为剩余至少2.54厘米的饲料）。适应期过后，试验1中的所有育肥牛都转换为CON牛栏并饲养至出栏。在试验2中，126头育肥牛（445.4±40.63千克）被随机分配到16个栏舍中的一个。试验2的处理采用2×2析因设计，包括试验1中使用的两种牛栏管理策略（OVF或CON）以及25%MDGS或50%MDGS（干物质基础）。在日粮适应期通过瘤胃穿刺测定瘤胃HS。在两项试验中，由于牛栏管理方式不同，生长性能方面均未观察到差异（P≥0.13）。在试验1中，OVF育肥牛在适应期的DMI更高（P = 0.001）；然而，各处理间的总体DMI并无差异（P = 0.14）。在试验2中，随着MDGS添加量增加，DMI（第0至104天）有降低趋势（P = 0.09）。热胴体重、眼肌面积、大理石花纹评分和质量等级均不受牛栏管理方式或MDGS添加量的影响（P≥0.48）。在试验2中，与OVF育肥牛相比，CON育肥牛的背膘厚（1.30厘米对1.17±0.042厘米）和产肉等级（3.2对3.0±0.11）更高（P = 0.03），但不受MDGS添加量的影响（P = 0.59）。在试验1中，与CON育肥牛相比，OVF育肥牛的HS有增加趋势（P = 0.07）。在试验2中，牛栏管理策略对HS浓度无影响（P = 0.82）。对于HS，存在MDGS添加量×天数的交互作用，在第28天和第35天，饲喂50%MDGS的育肥牛比饲喂25%MDGS的育肥牛HS浓度更高（P<0.01）。适应期的牛栏管理策略对生长性能无影响，但在试验1中确实降低了采食量。在试验2全程采用OVF牛栏管理方式时，产肉等级降低。瘤胃HS浓度的反应存在差异，可能受育肥期前期牛栏管理不一致以及由此导致的DMI的影响。
