This study aimed to assess the effect of preprocessing of corn and of physical form of diets on growth performance, carcass yield, and nutrient digestibility in broilers and also the influence of corn processing on pellet quality. A total of 1,080 male Cobb chicks from 1 to 35 D were evaluated. Birds were distributed according to a completely randomized design in a 3 × 2 factorial arrangement, with 3 types of corn processing (unprocessed, pelleted, or expanded), and 2 diet physical forms (mash or pelleted), totaling 6 treatments and 9 replicates with 20 birds. The data were submitted to ANOVA, and means were compared by Tukey's test (P < 0.05). There was no interaction between the physical form and preprocessing of corn for any of the studied variables (P > 0.05). The use of expanded corn in the diets before pelleting resulted in higher pellet durability index and lower amount of fines (P < 0.05) when compared with unprocessed corn. Broilers fed pelleted diets had higher feed intake (FI) and weight gain (WG; P < 0.001), higher amounts of abdominal fat (P < 0.05), and lower ileal digestible energy (IDE, P = 0.05) than those fed mash. There was no effect of the feed form on nutrient digestibility (P > 0.05). Broilers fed diets with unprocessed corn had higher FI when compared to those fed diets with expanded or pelleted corn (P < 0.001). The use of pelleted corn resulted in lower WG than the other processing methods (P < 0.01). The corn expansion process improved feed conversion ratio and adjusted feed conversion ratio (P < 0.001). Inclusion of expanded corn improved the coefficient of apparent ileal digestibility of DM, CP, starch, and IDE (P < 0.05) in comparison with unprocessed corn. It is concluded that pelleted diets improve broiler performance. The corn expansion can be used to improve physical quality of the diets and broilers growth performance and nutrient digestibility.

中文翻译：

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玉米的热加工和肉鸡日粮的物理形式。

这项研究旨在评估玉米的预处理和日粮的物理形式对肉鸡生长性能，car体产量和养分消化率的影响，以及玉米加工对颗粒品质的影响。评估了1到35 D的1,080只Cobb雄性雏鸡。按照完全随机的设计，以3×2因子分布方式分配禽鸟，包括3种类型的玉米加工（未加工，制粒或膨化）和2种日粮物理形式（捣碎或制粒），共进行6种处理和9种重复20只鸟。将数据提交给ANOVA，并通过Tukey检验比较均值（P <0.05）。对于任何研究变量，玉米的物理形态与预处理之间没有相互作用（P> 0.05）。与未加工的玉米相比，在制粒前在日粮中使用膨化玉米可以提高颗粒的耐久指数和减少细粉（P <0.05）。饲喂颗粒饲料的肉鸡比饲喂饲料的肉具有更高的采食量（FI）和体重增加（WG； P <0.001），更高的腹部脂肪含量（P <0.05）和较低的回肠可消化能量（IDE，P = 0.05）。饲料形式对养分消化率没有影响（P> 0.05）。与饲喂膨化或颗粒状玉米的肉鸡相比，饲喂未经加工的玉米肉鸡的FI更高（P <0.001）。与其他加工方法相比，使用粒状玉米可降低白粉病（P <0.01）。玉米膨化过程改善了饲料转化率，并调整了饲料转化率（P <0.001）。与未加工的玉米相比，包含膨化玉米可以改善DM，CP，淀粉和IDE的表观回肠消化率（P <0.05）。结论是颗粒饲料可以改善肉鸡的生产性能。玉米膨化可用于改善日粮的物理质量，提高肉鸡的生长性能和养分消化率。