Albro J D, Weber D W, DelCurto T
Department of Animal Sciences, Oregon State University, Corvallis 97331.
J Anim Sci. 1993 Jan;71(1):26-32. doi: 10.2527/1993.71126x.
Two experiments were conducted to compare whole, raw soybeans (WSB), extruded soybeans (ESB), and soybean meal+barley (SBM+BAR) as supplemental protein sources for growing beef steers consuming low-quality, mature grass hay (6.5% CP). In Exp. 1, a 23-d digestion study, four ruminally cannulated steers were assigned to the following treatments in a 4 x 4 Latin square design: 1) control, no supplement; 2) 1.5 kg.animal-1.d-1 of WSB; 3) 1.36 kg.animal-1.d-1 of ESB; and 4) 1.48 kg.animal-1.d-1 of 62%:38% SBM+BAR. Apparent DM digestibility was increased by supplementation (P < .10), but NDF digestibility was not changed (P > .10). No differences in digestibility were observed among supplement treatments (P > .10). In situ rate and extent of supplement CP disappearance in Dacron bags did not differ among supplements (P > .10), but extent of DM disappearance was greater for WSB than for ESB (P < .10). In situ rate of forage NDF disappearance was decreased by protein supplementation (P = .10). In Exp. 2, 40 Polled Hereford and Red Angus x Simmental weanling steer calves were stratified by weight (average BW, 250 kg) and allotted randomly to one of two replications of the four treatments used in Exp. 1 (eight pens, five animals per pen). Forage DMI was not affected by treatment (P > .10). Average daily gain and feed efficiency were increased by supplementation (P < .05). Supplement source had no effect on intake or ADG (P > .10), but ESB tended to exhibit better feed efficiency than WSB (P = .10). In conclusion, WSB and ESB seem to be as effective as SBM+BAR protein supplements for growing beef cattle. In addition, WSB and ESB, at the levels used in these experiments, can be incorporated into diets for cattle consuming low-quality roughage without deleterious effects on fiber digestion or subsequent performance.
进行了两项试验，以比较整粒生大豆（WSB）、挤压大豆（ESB）和豆粕+大麦（SBM+BAR）作为补充蛋白质来源，用于饲喂采食低质量成熟禾本科干草（粗蛋白含量6.5%）的生长育肥牛。在试验1中，进行了一项为期23天的消化研究，4头装有瘤胃瘘管的育肥牛按4×4拉丁方设计分配到以下处理组：1）对照组，不补充；2）每头动物每天1.5千克WSB；3）每头动物每天1.36千克ESB；4）每头动物每天1.48千克62%:38%的SBM+BAR。补充蛋白质提高了干物质表观消化率（P<0.10），但中性洗涤纤维消化率未改变（P>0.10）。各补充处理组间消化率无差异（P>0.10）。聚酯袋中补充蛋白质的原位消失率和程度在各补充剂间无差异（P>0.10），但WSB的干物质消失程度高于ESB（P<0.10）。补充蛋白质降低了饲草中性洗涤纤维的原位消失率（P=0.10）。在试验2中，40头无角海福特牛和红安格斯×西门塔尔断奶犊牛按体重分层（平均体重250千克），随机分配到试验1中使用的四种处理的两个重复之一（8个围栏，每个围栏5头动物）。饲草干物质采食量不受处理影响（P>0.10）。补充蛋白质提高了平均日增重和饲料效率（P<0.05）。补充剂来源对采食量或平均日增重无影响（P>0.10），但ESB的饲料效率倾向于高于WSB（P=0.10）。总之，对于生长育肥牛，WSB和ESB似乎与SBM+BAR蛋白质补充剂一样有效。此外，在这些试验中使用的水平下，WSB和ESB可以添加到采食低质量粗饲料的牛的日粮中，而不会对纤维消化或后续性能产生有害影响。
