Gerrits W J, Dijkstra J, France J
Wageningen Institute of Animal Sciences, Wageningen Agricultural University, The Netherlands.
J Nutr. 1997 Jun;127(6):1229-42. doi: 10.1093/jn/127.6.1229.
This paper describes the development of a mechanistic model integrating protein and energy metabolism in preruminant calves of 80-240 kg live weight. The objectives of the model are to gain insight into the partitioning of nutrients in the body of growing calves and to provide a tool for the development of feeding strategies for calves in this weight range. The model simulates the partitioning of nutrients from ingestion through intermediary metabolism to growth, consisting of accretions of protein, fat, ash and water. The model contains 10 state variables, comprising fatty acids, glucose, acetyl-CoA and amino acids as metabolite pools, and fat, ash and protein in muscle, hide, bone and viscera as body constituent pools. Turnover of protein and fat is represented. The model also includes a routine to check possible dietary amino acid imbalance and can be used to predict amino acid requirements on a theoretical basis. The model is based on two experiments, specifically designed for this purpose. Simulations of protein and fat accretion rates over a wide range of nutrient input suggest that the model is sound. In can be used as a research tool and for the development of feeding strategies for preruminant calves.
本文描述了一个机理模型的开发，该模型整合了体重80 - 240千克的反刍前犊牛的蛋白质和能量代谢。该模型的目标是深入了解生长犊牛体内营养物质的分配情况，并为制定该体重范围内犊牛的饲养策略提供一种工具。该模型模拟了从摄入营养物质开始，经过中间代谢，到生长（包括蛋白质、脂肪、灰分和水分的积累）的营养物质分配过程。该模型包含10个状态变量，包括作为代谢物池的脂肪酸、葡萄糖、乙酰辅酶A和氨基酸，以及作为身体组成部分池的肌肉、皮肤、骨骼和内脏中的脂肪、灰分和蛋白质。模型体现了蛋白质和脂肪的周转情况。该模型还包括一个检查可能的日粮氨基酸不平衡的程序，可用于从理论上预测氨基酸需求。该模型基于专门为此目的设计的两个实验。在广泛的营养输入范围内对蛋白质和脂肪积累率的模拟表明该模型是合理的。它可作为一种研究工具，用于制定反刍前犊牛的饲养策略。
