Abstract To determine the true ileal P digestibility coefficient of soybean meal (SBM), a total of 384 broilers (Cobb 500) at 21 days old, 192 males and 192 females, were arranged in a 3 х 2 (three total P levels x sex) factorial assay in a completely randomized design, with eight replicates and eight birds per experimental unit. The levels of total P in the experimental diets were 2.8, 3.5 and 4.2 g/kg. Increases in total P levels were achieved with the exclusive inclusion of SBM. Diets were provided from 21 until 26 days old, when the ileal digesta of the birds were collected. After chemical analyses, the ileal digestible P content of the diets was plotted against total P concentration in a linear regression analysis. The slope of the regression line gives the true ileal P digestibility coefficient of SBM. There was no interaction between sex and total P of diets (P > 0.05). There was linear increase in ileal P digestible content (P

中文翻译：

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豆粕对雄性和雌性肉鸡的真回肠磷消化率

摘要 为了测定豆粕（SBM）的真回肠磷消化率系数，将 384 只 21 日龄肉鸡（Cobb 500），192 只雄性和 192 只雌性，按 3×2（三个总磷水平 x ) 完全随机设计的析因分析，每个实验单元有 8 个重复和 8 只鸟。实验日粮中的总磷水平为 2.8、3.5 和 4.2 g/kg。独家加入 SBM 可提高总 P 水平。日粮从 21 天到 26 天提供，此时收集家禽的回肠食糜。化学分析后，在线性回归分析中，将日粮的回肠可消化磷含量与总磷浓度作图。回归线的斜率给出了 SBM 的真实回肠磷消化率系数。性别与日粮总磷之间没有交互作用（P > 0.05）。回肠可消化磷含量呈线性增加（P