Bateki Christian A, Dickhoefer Uta
University of Hohenheim, Animal Nutrition and Rangeland Management in the Tropics and Subtropics, 70599 Stuttgart, Germany.
Animals (Basel). 2020 May 8;10(5):816. doi: 10.3390/ani10050816.
Ruminant livestock systems in the (Sub-)Tropics differ from those in temperate areas. Yet, simulation models used to study resource use and productive performance in (sub-)tropical cattle production systems were mostly developed using data that quantify and characterize biological processes and their outcomes in cattle kept in temperate regions. Ergo, we selected the LIVestock SIMulator (LIVSIM) model, modified its cattle growth and lactation modules, adjusted the estimation of the animals' metabolizable energy and protein requirements, and adopted a semi-mechanistic feed intake prediction model developed for (sub-)tropical stall-fed cattle. The original and modified LIVSIM were evaluated using a meta-dataset from stall-fed dairy cattle in Ethiopia, and the mean bias error (MBE), the root mean squared error of prediction (RMSEP), and the relative prediction error (RPE) were used to assess their accuracy. The modified LIVSIM provided more accurate predictions of voluntary dry matter intake, final body weights 140 days postpartum, and daily milk yields than the original LIVSIM, as shown by a lower MBE, RMSEP, and RPE. Therefore, using data that quantify and characterize biological processes from (sub-)tropical cattle production systems in simulation models used in the (Sub-)Tropics can considerably improve their accuracy.
（亚）热带地区的反刍家畜养殖系统与温带地区不同。然而，用于研究（亚）热带肉牛生产系统中资源利用和生产性能的模拟模型，大多是利用量化和描述温带地区肉牛生物过程及其结果的数据开发的。因此，我们选择了家畜模拟器（LIVSIM）模型，修改了其肉牛生长和泌乳模块，调整了动物可代谢能量和蛋白质需求的估计，并采用了一个为（亚）热带舍饲肉牛开发的半机械采食量预测模型。使用来自埃塞俄比亚舍饲奶牛的元数据集对原始LIVSIM模型和修改后的模型进行了评估，并使用平均偏差误差（MBE）、预测均方根误差（RMSEP）和相对预测误差（RPE）来评估其准确性。如较低的MBE、RMSEP和RPE所示，修改后的LIVSIM模型对自愿干物质采食量、产后140天的最终体重和日产奶量的预测比原始LIVSIM模型更准确。因此，在（亚）热带地区使用的模拟模型中，使用量化和描述（亚）热带肉牛生产系统生物过程的数据可以显著提高其准确性。
