Department of Animal and Food Sciences, University of Kentucky, Lexington, KY 40546.
Alltech Inc., Nicholasville KY, USA.
Poult Sci. 2018 Jun 1;97(6):2106-2112. doi: 10.3382/ps/pey049.
For accurate estimation of nutrient digestibility, an ideal drying and sampling method is required to preserve the quality of the digesta. A standard corn-soybean meal (corn-SBM) broiler starter diet was fed from d 0 to 10 before birds were placed on the experimental diets until d 21. One hundred and sixty-eight male Cobb 500 broiler chicks were used to evaluate the effect of two drying methods (freeze-dryer vs. forced air-oven) and two drying temperatures (40 vs. 55°C) (Exp 1), while ninety-six chicks were used to evaluate the effect of flushing and squeezing as well as marker types (titanium vs. chromium) on apparent ileal DM, N, Ca, P, and AA digestibility (Exp 2). There were seven (Exp 1) or eight (Exp 2) replicate cages per treatment with 6 birds/cage. Digesta from the distal two thirds of the ileum was obtained from birds following euthanasia on d 21 by squeezing (Exp 1) and squeezing or flushing (Exp 2). Samples collected were stored in the freezer at -20°C until they were either freeze-dried (FD) or oven-dried (OD) at 40 or 55°C. There were no interactions between the drying methods and drying temperatures (Exp 1) on apparent ileal DM, N, and AA digestibility. Met had the highest (92.3%) while Cys had the lowest (73.8%) digestibility value. In Exp 2, no interaction between sampling methods and marker types was observed. The effect of sampling methods was not significant except for Arg and Met where squeezing resulted in higher (P < 0.05) digestibility values. Furthermore, apparent ileal His, Ile, Cys, Ser, and Tyr digestibility tended to be higher (P < 0.1) in squeezed digesta compared to the flushed digesta. Results from these studies showed that OD ileal digesta at 40 or 55°C had no negative effect on apparent ileal AA digestibility. Likewise, marker type did not influence apparent ileal AA digestibility values.
为了准确估计养分消化率，需要一种理想的干燥和采样方法来保持消化物的质量。在将雏鸡置于实验日粮上之前，从第 0 天到第 10 天给雏鸡喂食标准的玉米-豆粕（玉米-SBM）肉鸡起始日粮。使用 168 只雄性科宝 500 肉鸡雏鸡来评估两种干燥方法（冷冻干燥器与强制空气烘箱）和两种干燥温度（40°C 与 55°C）的影响（实验 1），而 96 只雏鸡用于评估冲洗和挤压以及示踪剂类型（钛与铬）对表观回肠 DM、N、Ca、P 和 AA 消化率的影响（实验 2）。每个处理有 7 个（实验 1）或 8 个（实验 2）重复笼，每个笼有 6 只鸡。在第 21 天通过挤压（实验 1）和挤压或冲洗（实验 2）从安乐死的雏鸡的回肠后 2/3 段获得消化物。收集的样品储存在-20°C 的冰箱中，直到在 40 或 55°C 下进行冷冻干燥（FD）或烘箱干燥（OD）。在表观回肠 DM、N 和 AA 消化率方面，干燥方法和干燥温度之间没有相互作用（实验 1）。Met 的消化率最高（92.3%），而 Cys 的消化率最低（73.8%）。在实验 2 中，未观察到采样方法和示踪剂类型之间存在相互作用。除 Arg 和 Met 外，挤压的消化率较高（P<0.05）外，其他采样方法的效果不显著。此外，与冲洗消化物相比，挤压消化物中的表观回肠 His、Ile、Cys、Ser 和 Tyr 消化率趋于更高（P<0.1）。这些研究的结果表明，在 40°C 或 55°C 下进行 OD 回肠消化物对表观回肠 AA 消化率没有负面影响。同样，示踪剂类型也不会影响表观回肠 AA 消化率值。
