Disentangling the relative roles of resource acquisition and allocation on animal feed efficiency: insights from a dairy cow model

摘要: Feed efficiency of farm animals has greatly improved through genetic selection for production. Today, we are faced with the limits our ability to predict effect on feed efficiency, partly because relative importance components this complex phenotype changes across environments. Thus, developed a dairy cow model that incorporates dynamic interplay between life functions and evaluated its behaviour global sensitivity analysis two definitions efficiency. A key feature is consider as result processes, acquisition allocation resources. Acquisition encapsulates intake digestion, partitioning rules physiological functions. The generates genetically-driven trajectories energy allocation, four genetic-scaling parameters controlling these processes. Model was assessed complete factorial design. had contrasting effects (ratio in milk acquired from environment). When measured over lactation period, increased by increasing lactation. However, at lifetime level, decreasing growth acquisition. While there strong linear increase more within cycle, results suggest an optimal level beyond which negatively affects We show breaking-down conversion into introducing control mechanisms, permitted quantification their roles stage appears be aspect selection. In model, body reserves also component prediction since they integrate feedback survival reproduction. This modelling approach provided new insights processes underpin cows.