Reduction of the particle size of corn increases energy digestibility and concentrations of digestible and metabolizable energy. Pelleting may also reduce particle size of grain, but it is not known if there are interactions between particle size reduction and pelleting. The objective of this experiment was to test the hypothesis that particle size reduction and pelleting, separately or in combination, increase N balance, apparent total tract digestibility (ATTD) of fiber and fat, and net energy (NE) in corn-soybean meal diets fed to group-housed pigs. Six corn-soybean meal-based diets were used in a 3 × 2 factorial design with 3 particle sizes of corn (i.e., 700, 500, or 300 μm) and 2 diet forms (i.e., meal or pelleted). Pigs were allowed ad libitum access to feed and water. Twenty-four castrated male pigs (initial weight: 29.52 kg; standard diviation: 1.40) were allotted to the 6 diets using a 6 × 6 Latin square design with 6 calorimeter chambers (i.e., 4 pigs/chamber) and 6 periods. Oxygen consumption and CO2 and CH4 productions were measured during fed and fasting states and fecal and urine samples were collected. Regardless of particle size of corn, the ATTD of gross energy (GE), N, and acid-hydrolyzed ether extract (AEE), and the concentration of NE were greater (P < 0.05) in pelleted diets than in meal diets. Regardless of diet form, the ATTD of GE, N, and AEE, and the concentration of NE were increased (linear; P < 0.05) by reducing the particle size of corn, but the increase was greater in meal diets than in pelleted diets (interaction; P < 0.05). Both pelleting and reduction of corn particle size increased nutrient digestibility and NE, but increases were greater in meal diets than in pelleted diets.

中文翻译：

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玉米制粒和粒度减小可增加群养猪饲喂的玉米-豆粕日粮中纤维、蛋白质和脂肪的净能量和消化率

玉米颗粒尺寸的减小提高了能量消化率以及可消化和可代谢能量的浓度。制粒还可以减小谷物的粒径，但尚不清楚粒径减小和制粒之间是否存在相互作用。本实验的目的是检验以下假设：颗粒尺寸减小和制粒单独或组合可增加玉米-豆粕日粮中的氮平衡、纤维和脂肪的表观总消化道消化率 (ATTD) 以及净能 (NE)喂给群养的猪。 6 种基于玉米-豆粕的日粮采用 3 × 2 析因设计，具有 3 种玉米颗粒尺寸（即 700、500 或 300 μm）和 2 种日粮形式（即粗粉或颗粒）。允许猪随意获取饲料和水。将 24 头去势公猪（初始体重：29.52 kg；标准偏差：1.40）分配至 6 个日粮，采用 6 × 6 拉丁方设计，具有 6 个量热器室（即 4 头猪/室）和 6 个周期。在进食和禁食状态下测量耗氧量以及二氧化碳和甲烷的产生，并收集粪便和尿液样本。无论玉米颗粒大小如何，颗粒日粮中总能（GE）、氮和酸水解乙醚提取物（AEE）的ATTD以及NE浓度均高于粗粉日粮（P < 0.05）。无论哪种日粮形式，GE、N 和 AEE 的 ATTD 以及 NE 浓度都随着玉米粒径的减小而增加（线性；P < 0.05），但粗粮日粮中的增加幅度大于颗粒日粮（相互作用；P < 0.05）。制粒和减小玉米颗粒尺寸都增加了养分消化率和NE，但粗粮日粮中的增加幅度大于颗粒日粮。