The objective of this study was to evaluate the potential of in vivo bioimpedance analysis (BIA) as a method to estimate body composition in lambs. Thirty-one Texel x Ile de France crossbreed ram lambs were slaughtered at pre-determined intervals of average weights of 20, 26, 32, and 38 kg. Before the slaughter of the animals, their body weight (BW) and body length (BL) were measured. The values for resistance (Rs) and reactance (Xc) were collected using a single-frequency BIA equipment (Model RJL Quantum II Bioelectrical Body Composition Analyzer). The BIA main variables such as body bioelectrical volume (V), phase angle (PA), resistive density (RsD), and reactive density (XcD) were then calculated. The soft tissue mass of the right-half cold carcass was analyzed in order to determine its chemical composition. Multiple regression analyses were performed using the lamb body composition as dependent variables and the measurements related to bioimpedance as independent variables. The best regression models were evaluated by cross-validation. The predictive model of moisture mass, which was developed by using XcD and V, accounted for 84% of its variation. Resulting models of percentage moisture (R² = 0.79), percentage lean mass (R² = 0.79), percentage fat (R² = 0.79), and fat mass (R² = 0.87) were obtained using RsD and V. Furthermore, the values of RsD regarding V, and PA in the prediction models accounted for 91% and 89% of variation in protein mass and lean mass, respectively. Bioimpedance analysis proved to be an efficient method to estimate the body composition of lambs slaughtered at different body mass stages.

这项研究的目的是评估体内潜能生物阻抗分析（BIA）作为估算羔羊体内成分的方法。以预定的平均体重20公斤，26公斤，32公斤和38公斤的间隔宰杀31头特塞尔x法兰西岛的杂交公羊羔。在宰杀动物之前，先测量它们的体重（BW）和体长（BL）。使用单频BIA设备（RJL Quantum II型生物电体成分分析仪）收集电阻（Rs）和电抗（Xc）的值。然后计算出BIA主要变量，例如人体生物电体积（V），相角（PA），电阻密度（RsD）和反应密度（XcD）。分析右半冷cold体的软组织质量，以确定其化学组成。使用羔羊的身体成分作为因变量，与生物阻抗相关的测量值作为自变量进行多元回归分析。最佳回归模型通过交叉验证进行评估。通过使用XcD和V开发的水分质量预测模型占其变化的84％。得出的湿度百分比模型（R²  = 0.79）， 使用RsD和V获得瘦体重百分率（R ²  = 0.79），脂肪百分率（R ²  = 0.79）和脂肪质量（R ² = 0.87）。预测模型中的PA分别占蛋白质质量和瘦肉质量变化的91％和89％。生物阻抗分析被证明是估算在不同体重阶段被宰杀的羔羊的身体成分的有效方法。