Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton AB T6G 2P5, Canada.
Institute of Animal Science, University of Hohenheim, 70599 Stuttgart, Germany.
J Anim Sci. 2023 Jan 3;101. doi: 10.1093/jas/skad204.
Fermentable fiber may increase endogenous losses of phosphorus (EPL) and amino acids (AA), thereby reducing apparent nutrient digestibility. Acacia gum with medium-to-high fermentability and low viscosity was increasingly included in diets to investigate its effect on apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients, gross energy (GE), and standardized total tract digestibility (STTD) of P in growing pigs. A control diet (49% cornstarch; 18% bovine plasma protein) was formulated to measure basal EPL. Three additional diets were formulated to include 2.5%, 5.0%, or 7.5% acacia gum at the expense of cornstarch. Diets contained 16.1% to 17.4% CP and 0.31% to 0.33% total P (DM-basis). The four diets were fed to eight ileal-cannulated barrows (initial BW, 54.6 kg) for four 9 d periods in a double 4 × 4 Latin square. Apparent hindgut fermentation (AHF) was calculated as ATTD minus AID. Feeding increasing acacia gum quadratically affected (P < 0.05) AID of DM, GE, linearly decreased (P < 0.05) ATTD of DM, crude protein (CP), GE, digestible (DE) and predicted net energy (NE) value of diets, and linearly increased (P < 0.001) AHF of DM and GE. Increasing acacia gum did not affect AID and standardized ileal digestibility (SID) of CP and AA. Basal EPL was 377 mg/kg DM intake (DMI) and increasing acacia gum linearly increased (P < 0.05) total tract EPL. Increasing acacia gum linearly decreased (P < 0.05) diet ATTD of P, and STTD of P based on either the calculated EPL or NRC (2012) recommended value (190 mg P/kg DMI). Increasing acacia gum did not affect AID and ATTD of Ca of diets. In conclusion, feeding increasing dietary fermentable, low-viscous acacia gum decreased diet AID and ATTD of DM and GE, but did not affect AID or SID of CP and AA. Increasing acacia gum decreased ATTD of P, which might have been due to increased specific endogenous losses of P in the total tract of growing pigs.
发酵纤维可能会增加内源磷（EPL）和氨基酸（AA）的损失，从而降低表观养分消化率。具有中高发酵性和低粘度的阿拉伯胶被越来越多地添加到饲料中，以研究其对生长猪养分表观回肠消化率（AID）和表观全肠道消化率（ATTD）、总能（GE）以及磷标准化总肠道消化率（STTD）的影响。设计对照饲粮（49%玉米淀粉；18%牛血浆蛋白）以测定基础 EPL。另外设计了 3 种饲粮，分别用 2.5%、5.0%或 7.5%的阿拉伯胶替代玉米淀粉。饲粮的 CP 含量为 16.1%17.4%，总磷（DM 基础）含量为 0.31%0.33%。4 种饲粮分别饲喂 8 头回肠末端瘘管安装的生长猪（初始 BW 为 54.6kg），4 期 9d 的双 4×4 拉丁方试验。表观后肠发酵（AHF）为 ATTD 与 AID 的差值。随着阿拉伯胶添加量的增加，AID 的 DM、GE 呈二次曲线变化（P＜0.05），DM、CP、GE、可消化（DE）和预测净能（NE）值的 ATTD 线性降低（P＜0.05），DM 和 GE 的 AHF 线性增加（P＜0.001）。添加阿拉伯胶不影响 CP 和 AA 的 AID 和标准回肠消化率（SID）。基础 EPL 为 377mg/kgDM 采食量（DMI），随着阿拉伯胶添加量的增加，总肠道 EPL 线性增加（P＜0.05）。随着阿拉伯胶添加量的增加，饲粮 ATTD 的 P 线性降低（P＜0.05），基于计算 EPL 或 NRC（2012）推荐值（190mg P/kgDMI）的 P 的 STTD 也线性降低（P＜0.05）。添加阿拉伯胶不影响饲粮 Ca 的 AID 和 ATTD。总之，添加日粮中发酵性强、低粘度的阿拉伯胶会降低饲粮的 AID 和 DM、GE 的 ATTD，但不影响 CP 和 AA 的 AID 或 SID。添加阿拉伯胶会降低 P 的 ATTD，这可能是由于生长猪全肠道内特定的内源磷损失增加所致。
