Da Silva T E, Costa J H C
Department of Animal and Veterinary Sciences, the University of Vermont, Burlington, VT 05405.
JDS Commun. 2025 Jul 3;6(5):654-659. doi: 10.3168/jdsc.2025-0777. eCollection 2025 Sep.
Optimizing calf feeding strategies is critical for improving performance, health, and weaning transitions of preweaning animals. Despite the updated National Academies of Sciences, Engineering, and Medicine (NASEM, 2021) , decision support tools integrating these equations for simulating optimized calf feeding strategies remain limited. To address this gap, we developed and tested the CalfSim, a free, user-friendly decision support tool designed to simulate and optimize feeding plans for dairy calves. CalfSim incorporates inputs that farmers can readily collect, enabling users to establish baseline scenarios, explore "what-if" questions, and evaluate the impacts of nutritional strategies on calf performance and rearing cost. The tool is built based on NASEM (2021) equations, with adaptations for predicting energy-allowable growth and solid feed intake under varying conditions. CalfSim's performance predictions were assessed using data from 27 studies, 24 from the and 3 other unpublished studies (n = 76 treatments, 258 BW observations, and 1,585 calves), demonstrating accurate and precise predictions (root mean square error = 8.56 kg, R = 0.91, and concordance correlation coefficient = 0.93). However, farm-specific factors (e.g., disease incidence, environmental stress, genetics) can influence predictions, and these factors are not accounted for. This highlights the need for on-farm data to assist users in making more informed decisions (e.g., by comparing scenarios, calculating cost per kilogram of gain). CalfSim provides actionable insights for designing cost-effective feeding plans, making it a valuable resource for dairy nutritionists, farmers, students, and consultants.
优化犊牛饲养策略对于提高断奶前动物的生产性能、健康状况和断奶过渡至关重要。尽管美国国家科学院、工程院和医学院（NASEM，2021年）已更新相关标准，但用于模拟优化犊牛饲养策略的集成这些方程式的决策支持工具仍然有限。为了填补这一空白，我们开发并测试了CalfSim，这是一个免费的、用户友好的决策支持工具，旨在模拟和优化奶牛犊牛的饲养计划。CalfSim纳入了农民可以轻松收集的输入信息，使用户能够建立基线情景、探索“如果……会怎样”的问题，并评估营养策略对犊牛生产性能和饲养成本的影响。该工具基于NASEM（2021年）的方程式构建，并针对不同条件下预测能量允许生长和固体饲料摄入量进行了调整。使用来自27项研究的数据评估了CalfSim的性能预测，其中24项来自已发表研究，3项来自其他未发表研究（n = 76个处理、258次体重观察和1585头犊牛），结果表明预测准确且精确（均方根误差 = 8.56千克，R = 0.91，一致性相关系数 = 0.93）。然而，特定农场因素（如疾病发生率、环境压力、遗传因素）会影响预测，而这些因素并未被考虑在内。这凸显了需要农场特定数据来帮助用户做出更明智决策（例如，通过比较不同情景、计算每千克增重成本）。CalfSim为设计具有成本效益的饲养计划提供了可操作的见解，使其成为奶牛营养学家、农民、学生和顾问的宝贵资源。
