In-depth analysis of supernumerary piglets management using new functionalities of PertMat

Abstract. The expert tool PertMat developed by Ifip-Institut du Porc performs automatic pre-weaning mortality profiling and detection of main risk factors in pig farms. First results showed that large litter size was the major limiting factor in most of the cases and poor adjustment of liveborn piglets to teat numbers was suspected. Therefore, new functionalities have been implemented in PertMat to investigate the importance of supernumerary piglets, the efficiency of litter management practices and interactions between mortality risk factors. PertMat uses individual farm data collected by management software and stored in the French National Pig Management database (GTTT). It is supported by IFIP GT-DIRECT Web platform and no additional information is required. Farmers’ results are compared to contemporary litters (#1,200 farms, over 700,000 litters each year). In a first step, the importance of supernumerary liveborn piglets is evaluated for each litter. Calculations take into account litter modifications and a functional teat number hypothesis. Depending on farms, registered litter management practices may include different solutions implemented at various rates: cross-fostering, nurse sows (1 or 2 step) and early weaning. In a given herd, PertMat analyses the impact of these different strategies on preweaning mortality and provides comparisons with other farms. This may help to deliver farm-specific comments about efficiency of supernumerary piglets management. Preweaning mortality is well known to have multifactorial inter-acting causes. Therefore first-step identification of single risk factors is completed by 9 to 20 cross analysis. This is applied to all calculated criteria: total born and live born mortality rates, still born and mummies rates. Analysis of the effect of litter size by parity, genetic, season or weekday provides more precise identification of limiting factors and action priorities. PertMat is a useful monitoring tool, but further evolutions may be required as more various practices have to be implemented to prevent the side effects of large litters.