DESCRIPTION OF A MODEL INTEGRATING PROTEIN AND ENERGY-METABOLISM IN PRERUMINANT CALVES

This paper describes the development of a mechanistic model integratin g protein and energy metabolism in preruminant calves of 80-240 kg liv e weight, The objectives of the model are to gain insight into the par titioning of nutrients in the body of growing calves and to provide a tool for the development of feeding strategies for carves in this weig ht range, The model simulates the partitioning of nutrients from inges tion through intermediary metabolism to growth, consisting of accretio ns of protein, fat, ash and water, The model contains 10 state variabl es, comprising fatty acids, glucose, acetyl-CoA and amino acids as met abolite pools, and fat, ash and protein in muscle, hide, bone and visc era as body constituent pools, Turnover of protein and fat is represen ted, 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, specifical ly designed for this purpose, Simulations of protein and fat accretion rates over a wide range of nutrient input suggest that the model is s ound, It can be used as a research tool and for the development of fee ding strategies for preruminant calves.