The current system for assessing the energy and protein requirements in dairy cows, growing cattle, and fattening cattle was introduced in Switzerland over 40 years ago. Updating it is essential to improve the efficiency of cattle farming systems, enhance economic performance and minimise their environmental impact, while integrating the latest scientific knowledge. Feed intake estimation and requirements for energy, protein, amino acids, minerals, and vitamins will be revised or newly introduced, partly based on the new German recommendations. Meanwhile, a mechanistic model for cattle growth and body composition will be optimised for beef cattle. Imaging techniques are used to measure total body volume for subsequent estimation of feed intake, to determine body composition in living cattle and to assess the mobilisation of minerals at the beginning of lactation. Additionally, factors at different levels of organisation (cell, tissue, animal) that influence feed efficiency and resilience of beef cattle will be investigated, alongside a holistic assessment of economic, environmental, and product quality aspects across all cattle categories.