The aim of the present study was to develop and evaluate an equation to predict body weight (BW) using hip width (HW) in Pelibuey ewe lambs and ewes. Five hundred seventy-seven 2-month-old to 3-year-old, non-pregnant, non-lactating, clinically healthy ewe lambs and adult ewes with a mean BW of 34.7 ± 12.4 kg and HW of 15.6 ± 3.4 cm were considered. Three equations were evaluated: BW (kg): − 19.17 + 3.46 × HW (Eq. 1), BW (kg): − 17.79 + 3.25 × HW + 0.007 × HW² (Eq. 2) and BW (kg): 0.39 × HW^1.63 (Eq. 3). Independent data from 80 animals with similar characteristics (BW of 23.4 ± 10.9 kg and HW of 12 ± 3.1 cm) were also considered to evaluate the developed equations. The evaluation was based on the relationship between the observed and predicted values of BW analysed using a linear regression, the mean squared error of prediction (MSEP), the root MSEP (RMSEP) and the concordance correlation coefficients (CCCs). Additionally, cross-validation analyses were performed using the k-folds validation (k = 10) procedure. The correlation coefficient (r) between BW and HW was 0.94 (P < 0.001). The parameters for precision and accuracy showed that the proposed equations had high precision (R² > 0.95%), accuracy (Cb > 0.98) and reproducibility (CCC > 0.96) in predicting the BW of ewe lambs and adult ewes. Equation (1) accurately predicted observed BW, with a bias (observed − predicted) of 4.3 kg and RMSEP of 9.68% with respect to the observed BW (random error of 84.23%); it also generated the best prediction according to the residual mean squared prediction error, coefficient of determination and mean absolute error. In conclusion, the highly correlated relationship between BW and HW in Pelibuey ewe lambs and adult ewes under humid tropic conditions enabled the development of mathematical models herein to estimate BW with an adequate goodness of fit. The linear model showed the best performance according to the goodness-of-fit evaluation and internal and external validation; hence, this model is proposed for use in both the experimental and commercial farms.

本研究的目的是开发和评估方程式，以使用Pelibuey母羊羔和母羊的臀围宽度（HW）预测体重（BW）。577名2个月至3岁，未怀孕，不哺乳，临床健康的母羊羔羊和成年母羊被认为平均体重为34.7±12.4千克，而体重为15.6±3.4厘米。评估了三个方程：BW（kg）：− 19.17 + 3.46×HW（方程1），BW（kg）：− 17.79 + 3.25×HW + 0.007×HW ²（方程2）和BW（kg）：0.39 ×硬件^1.63（式3）。还考虑了来自80只具有类似特征（体重23.4±10.9千克，体重12±3.1厘米）的动物的独立数据，以评估所开发的方程。评估基于使用线性回归分析的BW观测值和预测值之间的关系，预测均方误差（MSEP），根MSEP（RMSEP）和一致性相关系数（CCC）。另外，使用k倍验证（k  = 10）程序执行交叉验证分析。BW和HW之间的相关系数（r）为0.94（P  <0.001）。精度和精度的参数表明，该方程具有较高的精度（R ² > 0.95％），准确度（Cb> 0.98）和重现性（CCC> 0.96）在预测母羊羔羊和成年母羊的体重方面。等式（1）精确地预测了观察到的体重，相对于观察到的体重有4.3kg的偏差（观察到的-预测值）和RMSEP为9.68％（随机误差为84.23％）；它还根据残差均方预测误差，确定系数和平均绝对误差生成最佳预测。总之，湿润热带条件下的Pelibuey母羊羔羊和成年母羊的BW与HW之间高度相关的关系使本文的数学模型得以开发，从而可以估算出具有足够拟合优度的BW。根据拟合优度评估以及内部和外部验证，线性模型显示出最佳性能；因此，