Development of a novel reference feed intake model for Atlantic salmon (Salmo salar) based on temperature and body weight

Precision aquaculture requires the use of advanced technologies to optimize fish management. Substantial progress has been achieved in modeling Atlantic salmon (Salmon salar) growth and feeding behavior. However, there is still no simple mathematical model to predict feed intake that can be used for reference and benchmarking. This study aims to infer basic parametrized equations for Atlantic salmon feed intake using a minimal number of predictors: body weight and temperature. We used data from 64 previous publications and 25 commercial feeding tables. Various mathematical models were tested, incorporating different temperature functions and fitting methods. The following model provided the most accurate predictions under a wider range of temperatures and fish body weights:

$\mathrm{FI}=0.006\times {\mathrm{BW}}^{0.80}\times e^{\left(0.287\times \mathrm{temperature}-0.012\times {\mathrm{temperature}}^2\right)}$

where FI is the feed intake (g/fish/day), BW the average body weight of fish (g) and temperature the water temperature (°C). Using simple least squares and robust fitting methods yields better prediction capacities, while data from commercial feeding tables does not significantly enhance model accuracy. This basic reference model developed on this study can be readily used as an applied tool, e.g. estimating the feed amount required for production or trials, determining baseline feed intake when building more complex models accounting for other factors, developing growth models taking feed intake as input, evaluating current feeding practices. Its simplicity, adaptability, and broad applicability represent a valuable contribution to the field, providing a practical foundation for future model development and decision-making in Atlantic salmon farming management.