Buckhaus Elizabeth M, Rusche Warren C, Smith Zachary K
Department of Animal Science, South Dakota State University, Brookings, SD 57007, USA.
Animals (Basel). 2021 Jan 6;11(1):99. doi: 10.3390/ani11010099.
Continental crossbred beef heifers were used in a randomized complete block design experiment to evaluate the effects of replacement of dry-rolled corn with unprocessed rye on the finishing-phase growth performance and efficiency of dietary net energy (NE) use. Fifty-six heifers (433 ± 34.0 kg) were transported 241 km from a sale barn in North Central South Dakota to the Ruminant Nutrition Center in Brookings, SD. Heifers were blocked by weight grouping and allotted to treatment pens ( = 7 heifers/pen and 4 pens/treatment). Treatments included a finishing diet that contained 60% grain (diet dry matter basis) as dry-rolled corn (DRC) or unprocessed rye grain (RYE). On study day 14, all heifers were consuming the final diet and were implanted with 200 mg of trenbolone acetate and 28 mg of estradiol benzoate (Synovex-Plus, Zoetis, Parsippany, NJ, USA). The RYE heifers had decreased ( ≤ 0.01) final body weight, average daily gain, and gain efficiency; however, they tended ( = 0.08) to have a greater dry matter intake compared to DRC heifers. RYE heifers had decreased ( ≤ 0.01) observed dietary NE and decreased ( ≤ 0.01) observed-to-expected dietary NE ratio for maintenance and gain compared to DRC heifers. The dressing percentage, 12th rib fat thickness, ribeye area, and the distribution of yield and quality grades were not altered ( ≥ 0.12) by dietary treatment. The hot carcass weight, calculated yield grade, estimated empty body fat (EBF), and body weight at 28% EBF decreased ( ≤ 0.02) and retail yield increased ( = 0.01) in RYE compared to DRC heifers. These data indicate that unprocessed rye is a palatable feed ingredient for inclusion in finishing diets for beef cattle and that rye inclusion only minimally influences the carcass quality grade. The feeding value of unprocessed rye is considerably less (21.4%) than that of dry-rolled corn using current standards and approximately 91% of the NE value of processed rye (processing index = 78.8%). Rye grain fed as processed or unprocessed grain has an NE value that is less than 90% of that of dry-rolled corn.
在一项随机完全区组设计试验中，使用了大陆杂交肉牛小母牛，以评估用未加工的黑麦替代干碾压玉米对育肥期生长性能和日粮净能（NE）利用效率的影响。56头小母牛（433±34.0千克）从南达科他州中北部的一个拍卖场被运至241公里外的南达科他州布鲁金斯的反刍动物营养中心。小母牛按体重分组进行分栏，并分配到处理栏中（每栏7头小母牛，每个处理4栏）。处理包括一种育肥日粮，其含有60%的谷物（基于日粮干物质），分别为干碾压玉米（DRC）或未加工的黑麦谷物（RYE）。在研究的第14天，所有小母牛都采食最终日粮，并植入200毫克醋酸群勃龙和28毫克苯甲酸雌二醇（Synovex-Plus，美国佐治亚州帕西帕尼市的硕腾公司）。与DRC小母牛相比，RYE小母牛的最终体重、平均日增重和增重效率均有所下降（P≤0.01）；然而，它们的干物质摄入量有增加的趋势（P = 0.08）。与DRC小母牛相比，RYE小母牛维持和增重的实测日粮NE以及实测与预期日粮NE比值均有所下降（P≤0.01）。日粮处理对屠宰率、第12肋骨处脂肪厚度、眼肌面积以及产量和质量等级的分布没有影响（P≥0.12）。与DRC小母牛相比，RYE小母牛的热胴体重、计算出的产量等级、估计的空体脂肪（EBF）以及28%EBF时的体重均有所下降（P≤0.02），而零售产量有所增加（P = 0.01）。这些数据表明，未加工的黑麦是肉牛育肥日粮中一种可口的饲料成分，且黑麦的添加对胴体质量等级的影响很小。按照当前标准，未加工黑麦的饲喂价值比干碾压玉米低得多（21.4%），约为加工黑麦NE值的91%（加工指数=78.8%）。无论是以加工或未加工谷物形式饲喂的黑麦谷物，其NE值均低于干碾压玉米的90%。
