Division Académica de Ciencias Agropecuarias, Universidad Juárez Autónoma de Tabasco, Carr. Villahermosa-Teapa, km 25, CP 86280, Villahermosa, Tabasco, México.
Universidad Autónoma de Chiapas, Facultad de Medicina Veterinaria y Zootecnia, boulevard universitario km 2, CP 29520, Pichucalco, Chiapas, México.
J Dairy Res. 2020 Aug;87(3):341-343. doi: 10.1017/S002202992000076X. Epub 2020 Sep 4.
In this research communication we describe the creation of an equation for the prediction of milk yield (MY) from udder volume (UV). A total of 280 measurements were collected between 5 and 15 d postpartum (pp) from 36 multiparous Pelibuey ewes. Study variables were measured between 2 and 9 weeks pp and MY was measured by manual milking, UV prior to and following milking was measured using the technique of making moulds from aluminium foil. The MY ranged from 0.09 to 0.83 kg/d, meanwhile UV prior and following milking ranged from 155 to 1940 and 90 to 1520 cm3, respectively. Measurements of UV had a moderate to high (P < 0.01; 0.58 ≤ r ≤ 0.78) correlation with MY. The UV prior to milking was the best prediction model for MY, which explained 62% of the variation in MY. This equation presented moderate precision (r2 = 0.61) and high accuracy (bias correction factor = 0.94), confirming a good reproducibility index (concordance correlation coefficient = 0.73). Modelling efficiency (MEF = 0.59) showed moderate concordance between observed and predicted values. In conclusion, MY in lactating Pelibuey ewes could be predicted in a moderate way using the predictor variable UV measured with the technique of moulds made with aluminium foil.
在本研究通讯中,我们描述了一个从乳房体积(UV)预测奶产量(MY)的方程的创建。总共从 36 只经产佩利布尤羊收集了 280 个在产后 5 至 15 天(pp)之间的数据。研究变量在 pp 后 2 至 9 周之间进行测量,通过手工挤奶测量 MY,使用铝箔模具制作技术在挤奶前后测量 UV。MY 范围从 0.09 至 0.83 kg/d,而挤奶前后的 UV 范围分别为 155 至 1940 和 90 至 1520 cm3。UV 与 MY 之间具有中度至高度的相关性(P < 0.01;0.58 ≤ r ≤ 0.78)。挤奶前的 UV 是 MY 的最佳预测模型,解释了 MY 变化的 62%。该方程具有中等精度(r2 = 0.61)和高度准确性(偏差校正因子 = 0.94),确认了良好的再现性指数(一致性相关系数 = 0.73)。建模效率(MEF = 0.59)表明,观测值和预测值之间存在中度一致性。总之,使用铝箔模具制作技术测量的预测变量 UV 可以中等程度地预测泌乳期佩利布尤羊的 MY。