Modelling of growth and feed consumption of pigs from birth to slaughter : updating of the coefficients used to standardise the performance criteria in technical-economic management

Reference data make farmers aware of the performance level of their own farms, and help them analyse their results and improve productivity. Management practices vary greatly between farms therefore, in order to integrate these differences; standardised criteria have been calculated for fixed growing periods and used in the French technical economic management data base starting in 1991. There has been a marked improvement in growth performance over the last ten years. Therefore, the corrections which were initially created needed to be updated, in order to be more pertinent for actual performance levels.A Gompertz function was used to model the increase in pig body weight with age. The data for individual pig weights were collected in this study, from birth to slaughter at 145 kg. Linear regression was used to model the variations in cumulated feed intake with body weight during the post-weaning and growing-fattening periods. These relationships were then evaluated using data from the literature which indicated that the model could be adapted to data obtained in each piggery after making an adjustment, based on observed performance levels. Subsequently, these models allow the calculation of correction coefficients which can be applied to technical criteria measured on the farm, such as average daily gain and feed conversion ratio, and enable standardised performance values to be estimated..