Livestock feed intake assumptions in decision support tools; A stocktake of the current science and assumptions used by livestock models

Decision Support Tools (DSTs) and models are becoming increasingly important to make informed decisions. The aim of this review was to understand how the scientific assumptions behind related pasture-based DSTs used in New Zealand interrelate. Using modelled feed intake of grazing sheep as a case study, we reviewed the metabolisable energy (ME) assumptions of relevant New Zealand models. Although the DSTs were largely dependent on a common model, there were some discrepancies between them. We raise two concerns: 1. In New Zealand, pasture-based livestock models to predict ME intake are highly dependent on equations developed in Australia, not validated in New Zealand. 2. The minor discrepancies between models make collaboration difficult - this is particularly pertinent to farmer-targeted DSTs. Closer collaboration between DST companies and research institutions is required to agree on consistent, robust equations aligned with the latest scientific knowledge.