Staniar W B, Kronfeld D S, Hoffman R M, Wilson J A, Harris P A
Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0306, USA.
Equine Vet J. 2004 Mar;36(2):149-54. doi: 10.2746/0425164044868585.
Monitoring weight of foals is a useful management practice to aid in maximising athletic potential while minimising risks associated with deviations from normal growth.
To develop predictive equations for weight, based on linear measurements of growing Thoroughbreds (TBs).
Morphometric equations predicting weight from measurements of the trunk and legs were developed from data of 153 foals. The accuracy, precision and bias of the best fitting equation were compared to published equations using a naive data set of 22 foals.
Accuracy and precision were maximised with a broken line relating calculated volumes (V(t + l)) to measured weights. Use of the broken line is a 2 step process. V(t + l) is calculated from linear measures (m) of girth (G), carpus circumference (C), and length of body (B) and left forelimb (F). V(t + I) = ([G2 x B] + 4[C2 x F]) 4pi. If V(t + l) < 0.27 m3, weight is estimated: Weight (kg) = V(t + l) x 1093. If V(t + l) > or = 0.27 m3: Weight (kg) = V(t + l) x 984 + 24. The broken line was more accurate and precise than 3 published equations predicting the weight of young TBs.
Estimation of weight using morphometric equations requires attention to temporal changes in body shape and density; hence, a broken line is needed. Including calculated leg volume in the broken line model is another contributing factor to improvement in predictive capability.
The broken line maximises its value to equine professionals through its accuracy, precision and convenience.
监测马驹体重是一项有益的管理措施，有助于在将与正常生长偏差相关的风险降至最低的同时，最大限度地发挥运动潜力。
基于对成长中的纯种马（TBs）的线性测量，开发体重预测方程。
根据153匹小马驹的数据，建立了从躯干和腿部测量值预测体重的形态测量方程。使用22匹小马驹的原始数据集，将最佳拟合方程的准确性、精密度和偏差与已发表的方程进行比较。
将计算体积（V(t + l)）与测量体重关联的折线可使准确性和精密度最大化。使用折线是一个两步过程。V(t + l)根据胸围（G）、腕关节周长（C）、体长（B）和左前肢长度（F）的线性测量值（m）计算得出。V(t + I) = ([G2 x B] + 4[C2 x F])÷4π。如果V(t + l) < 0.27立方米，估计体重：体重（千克）= V(t + l) x 1093。如果V(t + l)≥0.27立方米：体重（千克）= V(t + l) x 984 + 24。该折线比3个已发表的预测年轻TBs体重的方程更准确、精密。
使用形态测量方程估计体重需要关注身体形状和密度的时间变化；因此，需要一条折线。在折线模型中纳入计算出的腿部体积是提高预测能力的另一个因素。
该折线通过其准确性、精密度和便利性，为马业专业人士最大化其价值。
