Department of Animal Science, University of Nebraska, Lincoln 68583-0908, USA.
J Anim Sci. 2012 Dec;90(12):4625-33. doi: 10.2527/jas.2010-3239. Epub 2012 Aug 2.
Calf-fed crossbred steers (n = 94) were randomly allocated to 3 dietary treatments (0%, 15%, or 30% wet distillers grains plus solubles, WDGS; DM basis) and fed for 167 d to determine the effects on quality attributes of beef. At 48 h postmortem, marbling score, marbling texture, and marbling distribution were assessed by a USDA grader. After grading, one rib eye slice (longissimus thoracis) »7 mm thick was excised from each carcass, trimmed of subcutaneous fat, and analyzed for fatty acid profile and lipid content. At 7 d postmortem, 48 top blades (infraspinatus), strip loins (longissimus lumborum), and tenderloins (psoas major) (16 per treatment) were removed from shoulder clods and short loins and 2 steaks were obtained to measure mineral content, fatty acid profile (except strip loins), trained sensory analysis, objective color, and lipid oxidation. Finishing diet did not influence the content of total lipid (P = 0.19) or marbling, marbling texture, or marbling distribution (P = 0.46, 0.84, 0.40, respectively). Feeding WDGS created a linear increase (P < 0.01) of PUFA in all three muscles (longissimus thoracis showed 4.90%, 5.91%, and 6.23% PUFA for 0%, 15%, and 30% WDGS, respectively). Similar responses were observed for 18:2(n-6) and total n-6 fatty acids. Conversely, lower proportions of 18:1(n-7) fatty acid were observed in beef from animals fed 30% WDGS (P < 0.01). Total trans fatty acids increased linearly in strip loin and top blade steaks (P < 0.01), whereas proportions of 16:0 and 14:1(n-5) fatty acids decreased in all muscles (P < 0.01) as WDGS increased. Diet did not affect mineral content of top blades or strip loins. For tenderloin steaks, S concentration was lower when 30% of WDGS was fed (P = 0.05). No effects on sensory attributes and Warner-Bratzler shear force were observed (P > 0.50), except a minimal effect on strip loin juiciness (5.32, 4.86, and 5.52 for 0%, 15%, and 30% WDGS, respectively; P = 0.02). Top blade and tenderloin steaks from cattle fed 30% WDGS were significantly less red (lower a* values) on d 3 of simulated retail display (P < 0.04). Inclusion of 30% WDGS in the diet resulted in higher levels of oxidation after 7 d of retail display for top blade and strip loin steaks (P < 0.01). Feeding WDGS to calf-fed steers altered fatty acid profile, increased oxidation, and decreased color stability during retail display.
育肥期 calves （n = 94）随机分配到 3 种日粮处理（0%、15%或 30%湿酒糟及其可溶性物（WDGS），干物质基础），饲养 167 天，以确定其对牛肉质量属性的影响。在屠宰后 48 小时，由美国农业部（USDA）分级员评定大理石花纹评分、大理石花纹质地和大理石花纹分布。分级后，从每头胴体上切下一片 7 毫米厚的肋眼切片（最长肌胸），修剪皮下脂肪，分析脂肪酸谱和脂质含量。在屠宰后 7 天，从肩部肉块和短肋中取出 48 个上肩（三角肌）、里脊（最长肌腰）和牛里脊（腰大肌）（每处理 16 个），并获得 2 块牛排以测量矿物质含量、脂肪酸谱（里脊除外）、训练感官分析、客观颜色和脂质氧化。育肥日粮不影响总脂质含量（P = 0.19）或大理石花纹、大理石花纹质地或大理石花纹分布（P = 0.46、0.84、0.40，分别）。WDGS 的喂养导致所有三种肌肉中的多不饱和脂肪酸（PUFA）呈线性增加（P < 0.01）（最长肌胸的 PUFA 分别为 4.90%、5.91%和 6.23%，0%、15%和 30%的 WDGS）。18:2（n-6）和总 n-6 脂肪酸也出现了类似的反应。相反，在喂食 30% WDGS 的牛肉中，18:1（n-7）脂肪酸的比例较低（P < 0.01）。在里脊和上肩牛排中，总反式脂肪酸呈线性增加（P < 0.01），而在所有肌肉中，16:0 和 14:1（n-5）脂肪酸的比例下降（P < 0.01）随着 WDGS 的增加。日粮不影响上肩或里脊的矿物质含量。对于牛里脊牛排，当喂食 30%的 WDGS 时，S 浓度较低（P = 0.05）。感官属性和 Warner-Bratzler 剪切力没有受到影响（P > 0.50），除了里脊嫩度有轻微影响（0%、15%和 30%的 WDGS 分别为 5.32、4.86 和 5.52；P = 0.02）。在模拟零售展示的第 3 天，喂食 30%WDGS 的牛里脊和牛里脊牛排的颜色明显较红（a*值较低）（P < 0.04）。在零售展示的第 7 天，在零售展示期间，WDGS 日粮的添加导致上肩和里脊牛排的氧化水平更高（P < 0.01）。育肥期 calves 喂食 WDGS 改变了脂肪酸谱，增加了氧化作用，并降低了零售展示期间的颜色稳定性。
