Felton E E D, Kerley M S
Department of Animal Science, University of Missouri, Columbia 65211, USA.
J Anim Sci. 2004 Mar;82(3):725-32. doi: 10.2527/2004.823725x.
Two experiments were conducted to determine the efficacy of whole raw soybeans as a partial or whole replacement for soybean meal in a corn/soybean meal-based feedlot diet. In Exp. 1, 80 crossbred steers (average BW = 441.3 kg) and, in Exp. 2, 96 Angus-sired steers (average BW = 413.7 kg) were blocked by weight and assigned randomly to one of four dietary treatments. Treatments were 0, 8, 16, and 24% dietary inclusions of whole raw soybeans. Diets within experiments were isonitrogenous. Across experiments, diets were similar, differing only in amount of corn silage (8 vs. 15% DM) at the expense of whole, shelled corn for Exp. 1 and Exp. 2, respectively. No treatment differences were observed for ADG or final BW. Dry matter intake from d 0 to d 58 decreased linearly (P < 0.05) with increased inclusion of whole raw soybeans in Exp. 1, with no effect on feed efficiency. In Exp.2 from d 0 to 72, whole raw soybean inclusion had no effect on DMI or feed efficiency. There tended (P < 0.10) to be a linear reduction in hot carcass weight when whole raw soybeans were included in Exp. 1. Unexpectedly, longissimus muscle area tended (P < 0.10) to respond quadratically (P < 0.10) to the increased inclusion of whole raw soybeans in Exp.1. No differences were detected in marbling score, 10th-rib backfat, or yield grade for Exp. 1 and 2 steers. In Exp. 2, inclusion of whole raw soybeans had no effect on hot carcass weight or longissimus muscle area. Incrementally increasing the inclusion of whole raw soybeans in the diet of feedlot steers had little overall effect on weight gain, feed efficiency, or carcass quality in Exp. 1 and 2. There were subtle differences in the treatment responses observed for hot carcass weight and longissimus muscle area between Exp. 1 and Exp. 2 for the 24% inclusion level. These noted differences may indicate that inclusion levels above 24% might not be beneficial.
进行了两项试验，以确定在基于玉米/豆粕的育肥牛日粮中，用全生大豆部分或全部替代豆粕的效果。在试验1中，选用80头杂交阉牛（平均体重=441.3千克），试验2中选用96头安格斯种公牛后代阉牛（平均体重=413.7千克），按体重进行分组，并随机分配到四种日粮处理组中的一组。处理方式为日粮中全生大豆的添加量分别为0%、8%、16%和24%。试验中的日粮粗蛋白含量相同。在两个试验中，日粮相似，仅玉米青贮料的含量不同（分别为8%和15%干物质），试验1和试验2中分别以全粒脱壳玉米为代价。在平均日增重（ADG）或最终体重方面，未观察到处理组间的差异。在试验1中，从第0天到第58天，随着全生大豆添加量的增加，干物质摄入量呈线性下降（P<0.05），但对饲料效率无影响。在试验2中，从第0天到第72天，全生大豆的添加对干物质摄入量或饲料效率无影响。在试验1中，当添加全生大豆时，热胴体重有线性下降的趋势（P<0.10）。出乎意料的是，在试验1中，随着全生大豆添加量的增加，背最长肌面积有二次反应的趋势（P<0.10）。试验1和试验2的阉牛在大理石花纹评分、第10肋背膘厚度或胴体等级方面未检测到差异。在试验2中，全生大豆的添加对热胴体重或背最长肌面积无影响。在试验1和试验2中，育肥牛日粮中全生大豆添加量的逐步增加对体重增加、饲料效率或胴体品质的总体影响较小。在24%添加水平下，试验1和试验2在热胴体重和背最长肌面积的处理反应上存在细微差异。这些差异可能表明，添加量超过24%可能并无益处。
