影響飼料原料能量含量的營養物質包括小分子碳水化合物，但是原料物理性狀無法用來...

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　　影響飼料原料能量含量的營養物質包括小分子碳水化合物，但是原料物理性狀無法用來預測體外干物質消化率
　　2018. J. Anim. Sci. 96(2): 532-544

　　原文鏈接：https://academic.oup.com/jas/article/96/2/532/4828205
　　DOI: 10.1093/jas/sky010

　　影響飼料原料能量含量的營養物質包括小分子碳水化合物，但是原料物理性狀無法用來預測體外干物質消化率
　　D. M. D. L. Navarro, E. M. A. M.Bruininx, L. de Jong, and H. H. Stein

　　翻譯： 王鈺明  校對： 上海亙泰實業集團

　　本文通過一個試驗定量測定飼料原料中的營養素和纖維組分，并測定原料干物質和有機物的體外表觀回腸消化率（IVAID）和體外表觀全腸道消化率（IVATTD）。

　　本試驗選用了十種纖維含量和組成不同的原料：玉米、小麥、豆粕（SBM）、菜籽粕、干酒糟及其可溶物（DDGS）、玉米胚芽粕、椰子渣、甜菜渣（SBP）、混合纖維素和果膠。分別測定分析了原料的化學成分、物理特性和干物質、有機物的IVAID、IVATTD之間的相關關系。其中物理特性包括容重、系水力（WBC）、溶脹度和黏度。同時還對總能（GE）的計算值（根據原料的組成成分提供能量進行計算）與測定值進行了比對。

　　結果表明大部分原料分析化學成分的總和可達100%或更高，而DDGS、甜菜渣和混合纖維素的營養組成加和后分別僅有94.29%、88.90%和96.09%。不同原料總能的計算值與測定值之間的差異從-2.25 MJ/kg（DDGS）到1.74MJ/kg（果膠）之間。原料中不可溶性纖維（IDF）和總纖維（TDF）的含量與干物質或有機物的IVAID和IVATTD呈顯著負相關(P< 0.05)，而NDF (r=&#8722;0.60)和ADF (r=&#8722;0.61)與干物質的IVAID有顯著負相關的趨勢(P< 0.10)。然而，原料的物理特性（溶脹度、系水力或黏度）與干物質、有機物的IVAID、IVATTD間并無顯著相關性，原料的其他化學組分粗蛋白質、總能、酸解脂肪、木質素、可溶性纖維與干物質、有機物的IVAID、IVATTD間也并無顯著相關性。此外，不可溶纖維、總纖維、不可溶性非淀粉多糖與干物質、有機物的IVAID、IVATTD的相關性要顯著高于ADF和NDF，說明飼料原料中總纖維的含量比NDF和ADF更適用于估測干物質、有機物的消化率。

　　綜上，一些原料總能的計算值同測定值一致，說明原料的能量貢獻組分可以被分解開來，但對于DDGS和甜菜渣來說這種方法并不能包括所有含能量的養分。飼料原料的不可溶性纖維和總纖維的含量可用來估測原料干物質、有機物的IVAID、IVATTD，而無法通過原料的物理特性來估測。

　　關鍵詞：能量，體外消化率，物理化學特性，總日糧纖維

　　Analysis for low-molecular-weight carbohydrates is needed to account for all energy-contributing nutrients in some feed ingredients, but physical characteristics do not predict in vitro digestibility of dry matter

　　D. M. D. L. Navarro, E. M. A. M.Bruininx, L. de Jong, and H. H. Stein

　　An experiment was conductedto quantify nutrient and fiber fractions of feed ingredients and to determinein vitro apparent ileal digestibility (IVAID) and in vitro apparent total tractdigestibility (IVATTD) of DM and OM in each ingredient. Ten ingredients thatvary in fiber concentration and composition were used: corn, wheat, soybeanmeal (SBM), canola meal, distillers dried grains with solubles (DDGS), corngerm meal, copra expellers, sugar beet pulp (SBP), synthetic cellulose (SF),and pectin. Correlations between chemical and physical characteristics ofingredients and IVAID and IVATTD of DM and OM were determined. The physical characteristics measured included bulk density, water-binding capacity (WBC),swelling, and viscosity. The analyzed GE was compared with values for GE calculated from all energy-contributing components. Results indicated that the analyzed chemical composition of most ingredients added to 100% or greater,except for DDGS, SBP, and SF, where nutrients added to only 94.29%, 88.90%, and96.09%, respectively. The difference between the sum of the calculated GE ofthe analyzed components and the analyzed GE of the ingredients ranged from&#8722;2.25 MJ/kg in DDGS to 1.74 MJ/kg in pectin. No correlation was observed between swelling, WBC, or viscosity and IVAID or IVATTD of DM or OM. The concentration of insoluble dietary fiber (IDF) and total dietary fiber (TDF) was negatively correlated (P < 0.05) with IVAID and IVATTD of DM and OM. There was a tendency for NDF (r = &#8722;0.60) and ADF (r = &#8722;0.61) to be negatively correlated (P < 0.10) with IVAID of DM. However, no correlation was observed between the concentration of CP, GE, acid-hydrolyzed ether extract, lignin, or soluble dietary fiber and IVAID and IVATTD of DM and OM. The stronger correlations between IDF, TDF, and insoluble non-starch polysaccharides and IVAID and IVATTDof DM and OM than between ADF and NDF and IVAID and IVATTD of DM and OM indicate that the concentration of TDF in feed ingredients is a better predictor of the digestibility of DM and OM than values for NDF and ADF. In conclusion, the calculated GE of some feed ingredients was in agreement withthe analyzed GE, which gives confidence that energy-contributing components were accounted for, but for DDGS and SBP, it was not possible to account forall analyzed GE. Concentrations of IDF and TDF, but not the physicalcharacteristics of feed ingredients, may be used to estimate IVAID and IVATTDof DM and OM in feed ingredients.

　　Key words: energy, in vitro digestibility, physicochemicalcharacteristics, total dietary fiber
　　轉自： 豬營養國際論壇CSIS