Re-parametrization of a swine model to predict growth performance of broilers

The aim of the study was to investigate whether a pig growth model is suitable to be modified and adapted to broilers. As monogastric animals, pigs and poultry share a lot of similarities in their digestion and metabolism. The common basis and the generic approach are feasible, considering that the stoichiometry of the underlying metabolic pathways is independent of species. For that purpose InraPorc was used as a basis that was developed to predict the growth performance and chemical composition of the body at slaughter by representing the energy and protein utilization in pigs. Firstly, the backbone of InraPorc model was translated to Excel and examined whether the equations are suitable for growing birds by studying the parameters and the model behavior. After determining of differences which are due to the magnitude and the efficiency of the transactions rather than having special metabolic processes, the model was modified for predicting the actual broiler production including various genetic potential in response to different nutrient supply. The model core is very generic in terms of representing the most important steps of nutrient flows and transformation from absorbed nutrients to protein and fat accretion for each further day of age. The idea of nutrient utilization is mainly based on concepts used in net energy and ideal protein systems. The model is driven by feed intake, the partitioning of energy between protein and lipid deposition, and availability of dietary protein and amino acids. Adjustment of the Gompertz function parameters from the literature was used for expressing maximum body protein deposition. Equations were integrated to estimate the feather growth and feather protein production over time. The amino acid loss with feather was considered as a part of maintenance requirement and maintenance energy need was defined to be the fasting heat production (FHP) calculated as 460*BW0.7 (kJ/day) according to literature data. Feed intake for broilers was expressed in net energy bases and estimated by Gamma-function such as in InraPorc. Parameters of Gamma function were adjusted to experimental data from different broiler studies. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 633531.