Abstract The objective was to evaluate the coefficients of total tract apparent digestibility (CTTAD) and metabolisable energy (ME) of raw soybeans (RSB) in extruded diets for dogs by three methods (difference, regression and substitution). We also evaluated the urease and trypsin inhibitor (TI) activity, CTTAD, ME and faecal characteristics of adult dogs fed diets containing increasing RSB levels. Six dogs, distributed in a 6 × 6 Latin square design, were fed extruded diets containing 0, 60, 120, 180, 240 or 300 g of RSB/kg. Urease and TI were reduced in all diets after extrusion (p < .01), but TI was not completely inactivated. The inclusion of RSB linearly reduced (p < .01) the digestibility of dry matter (DM), organic matter and crude protein (CP) and linearly increased (p < .05) the digestibility of fat and gross energy and the ME of diets. The CTTAD of DM, CP and fat, and ME of RSB, predicted by the substitution method were: 0.767, 0.758, 0.960 and 20.7 MJ/kg, respectively. The dietary inclusion of RSB reduced faecal DM content and promoted a quadratic increase (p < .01) of pH and ammonia. Increasing RSB in diet reduced CTTAD estimate errors (p < .05). When 300 g of RSB were added per kg of diet, CTTAD of RSB estimated by the three methods did not differ (p>.05). The three methods can be used to determine RSB digestibility. Diet extrusion may not be able to completely deactivate the protease inhibitors present in the RSB. Highlights Extrusion may not be able to deactivate protease inhibitors of raw soybeans. Raw soybeans reduce nutrient digestibility of extruded diets in dogs. The substitution method is recommended to evaluate digestibility of raw soybeans.

中文翻译：

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不同方法测定的狗用膨化日粮中生大豆的消化率

摘要 目的通过三种方法（差异、回归和替代）评估犬挤压日粮中生大豆（RSB）的总消化道表观消化率（CTTAD）和代谢能（ME）系数。我们还评估了饲喂含有不断增加的 RSB 水平的饮食的成年犬的脲酶和胰蛋白酶抑制剂 (TI) 活性、CTTAD、ME 和粪便特征。以 6 × 6 拉丁方设计分布的六只狗喂食含有 0、60、120、180、240 或 300 g RSB/kg 的挤压饲料。挤出后所有日粮中的脲酶和 TI 均降低（p < .01），但 TI 并未完全失活。加入 RSB 会线性降低 (p < .01) 干物质 (DM)、有机物质和粗蛋白 (CP) 的消化率并线性增加 (p < .01)。05) 脂肪和总能量的消化率以及日粮的 ME。通过替代方法预测的DM、CP和脂肪的CTTAD以及RSB的ME分别为：0.767、0.758、0.960和20.7 MJ/kg。饮食中添加 RSB 降低了粪便 DM 含量并促进了 pH 值和氨的二次增加 (p < .01)。增加饮食中的 RSB 减少了 CTTAD 估计误差（p < .05）。当每公斤日粮添加 300 克 RSB 时，三种方法估计的 RSB 的 CTTAD 没有差异（p>.05）。这三种方法可用于测定 RSB 消化率。饮食挤压可能无法完全灭活 RSB 中存在的蛋白酶抑制剂。亮点 挤压可能无法使生大豆的蛋白酶抑制剂失活。生大豆会降低狗挤压饲料的营养消化率。