Dilger R N, Sands J S, Ragland D, Adeola O
Department of Animal Sciences, Purdue University, West Lafayette, IN, USA.
J Anim Sci. 2004 Mar;82(3):715-24. doi: 10.2527/2004.823715x.
This study was designed to quantify the effect of soyhulls on N and AA digestibilities of soybean meal for growing pigs. Soyhulls were incorporated into 17% CP diets containing 33.25% soybean meal (SBM) at 0, 3, 6, or 9% (as-fed basis) and fed to 35-kg barrows to determine their effect on apparent and true digestibility of DM, GE, N, and AA measured at the terminal ileum. Positive and negative control diets containing 1.05% lysine were formulated with 35% SBM and 27% soy protein concentrate (SPC), respectively. A low-protein, casein-based diet was used to estimate endogenous AA losses. Soyhulls were incorporated into experimental diets at the expense of cornstarch, and SBM levels were adjusted to accommodate the contribution of CP from soyhulls. Fourteen pigs were surgically fitted with simple T-cannula at the distal ileum and fed the seven semipurified cornstarch diets based on a replicated 7 x 7 Latin square design. Each period lasted 7 d, with diet acclimation from d 1 to 5 and ileal sample collection for 12 h on d 6 and 7. Feed was offered at a level of 90 g/kg BW(0.75) in two equal portions at 0800 and 2000. Apparent ileal digestibilities of DM and GE decreased approximately six percentage units with the addition of soyhulls (linear, P < 0.05), whereas N was not affected. Both apparent and true ileal digestibilities of arginine, histidine, lysine, phenylalanine, aspartic acid, serine, and tyrosine also exhibited a decrease (linear, P < 0.05) of up to five percentage units with the addition of soyhulls. True ileal lysine digestibility of SBM decreased from 90.3 to 87.7% with the addition of 9% soyhulls. The endogenous nutrient fraction measured at the distal ileum was rich in proline, glutamic acid, and glycine, with losses greater than 1,000 mg/kg of DMI for each AA, and contained minimal amounts of tryptophan, methionine, and cystine. The current data suggest that a 0.2% decrease in some true ileal indispensable AA digestibilities may result with each 1% increase in soyhull inclusion in semipurified diets containing SBM as the sole source of AA as fed to growing pigs.
本研究旨在量化大豆皮对生长猪豆粕中氮和氨基酸消化率的影响。将大豆皮以0%、3%、6%或9%（风干基础）的比例添加到含17%粗蛋白且含有33.25%豆粕（SBM）的日粮中，并饲喂体重35 kg的公猪，以测定其对回肠末端干物质（DM）、总能（GE）、氮和氨基酸表观消化率及真消化率的影响。分别用35% SBM和27%大豆浓缩蛋白（SPC）配制含1.05%赖氨酸的正对照和负对照日粮。采用低蛋白、酪蛋白基础日粮来估计内源氨基酸损失。大豆皮以取代玉米淀粉的方式添加到试验日粮中，并调整SBM水平以适应大豆皮中粗蛋白的贡献。14头猪在回肠末端手术安装简单T型瘘管，并根据重复的7×7拉丁方设计饲喂7种半纯合玉米淀粉日粮。每个试验期持续7 d，第1至5天适应日粮，第6和7天收集12 h的回肠样品。以90 g/kg体重（0.75）的水平分两份在0800和2000等量提供饲料。添加大豆皮后，DM和GE的回肠表观消化率降低了约6个百分点（线性，P<0.05），而氮不受影响。添加大豆皮后，精氨酸、组氨酸、赖氨酸、苯丙氨酸、天冬氨酸、丝氨酸和酪氨酸的回肠表观消化率和真消化率也均出现降低（线性，P<0.05），降幅高达5个百分点。添加9%大豆皮后，SBM的回肠真赖氨酸消化率从90.3%降至87.7%。在回肠末端测定的内源营养成分中脯氨酸、谷氨酸和甘氨酸含量丰富，每种氨基酸的损失均大于1000 mg/kg干物质采食量（DMI），而色氨酸、蛋氨酸和胱氨酸含量极少。目前的数据表明，在以SBM作为生长猪日粮中唯一氨基酸来源的半纯合日粮中，大豆皮添加量每增加1%，某些回肠真必需氨基酸消化率可能会降低0.2%。
