Towards a biological basis for predicting nutrient partitioning: the dairy cow as an example

摘要: Prediction of nutrient partitioning is a long-standing problem animal nutrition that has still not been solved. Another substantial for nutritional science how to incorporate genetic differences into models. These two problems are linked as their biological basis lies in the relative priorities different life functions (growth, reproduction, health, etc.) and they change both through time response selection. This paper presents recent developments describing this evidence support concepts involved relate partitioning. There ample at stages reproductive cycle various metabolic pathways, such lipolysis lipogenesis, up or down regulated. The net result changes nutrients channelled differing extents organs, end-products. occurs homeostatic function changing environment but rather homeorhetic caused by expression genes processes milk production time. In other words, drives there an aspect genetically driven. Evidence than available discussed. Genetic just imply will lactation according genotype – i.e. it cannot be predicted from feed properties alone. Progress controls reviewed. currently lack good measures physiological parameters. unprecedented level detail amounts data generated advent microarray biotechnology fields genomics, proteomics, etc. should long-term provide necessary information make link between metabolism. However, gene expression, protein synthesis etc, have all shown environmentally sensitive. Thus, major challenge realising potential afforded new technology able distinguish driven effects on expression. To do we need better understanding interactions genotypes environments. limitations traditional evaluation £ plasticity discussed benefits considering these terms trade-offs put forward. Trade-offs place explicitly centre resource allocation allow consideration management selection multiple traits