Calibration and sensitivity analysis of a model of the growing pig for weight gain and composition

Abstract

The model concerned was a mechanistic model for pig growth and composition which was constructed using novel algorithms for the accumulation of protein and lipid. The model was parameterised using data collected from a serial slaughter trial of three different types of pigs and the sensitivity to parameters of biological importance was explored. The types (‘Landrace’ type, ‘Pietrain’ type and ‘Meishan’ type) were chosen to represent ‘lean’, ‘meaty’ and ‘fatty’ types. After optimisation, fitted parameters were found to lie close to the values that would be expected given the assumptions made during the construction of the model, with a predicted maximum protein retention rate of 0.20 kg d −1 and an efficiency of recapture of amino acids during turnover of 0.94. Mean absolute percentage errors at slaughter point for modelled live weight were ca. 5%, compared with 8% for protein mass and 13% for lipid mass, suggesting that live weight gain is easier to predict than the partitioning of biomass into retained protein and lipid.