Développement d'un outil d'aide à la décision pour l'alimentation de précision des truies en gestation

Nutritional studies indicate that nutrient requirements for pregnancy differ greatly among sows and by stage of pregnancy, but in practice the same diet is generally fed to all sows from a given herd. In this context, the availability of new technologies for high throughput phenotyping of sows and characterization of their environment, and of innovative feeders that can distribute different diets, offers opportunities for a renewed and practical implementation of predictive models of nutrient requirements, in the perspective of improving feed efficiency and reducing feeding costs and environmental impacts. The objective of this study was thus to design a decision support tool that could be incorporated into automated feeding equipment. The decision support tool was developed from the InraPorc® model. Optimal nutritional supply for a given sow is determined each day according to a factorial approach considering all the information available about the sow: genotype, parity, expected prolificacy, gestation stage, body condition (i.e. weight and backfat thickness), activity and housing (i.e. type of floor and ambient temperature). The approach was tested using data from 2511 pregnancies on 540 sows. Energy supply was calculated for each sow to achieve, at farrowing, a target body weight established based on parity and age at mating, and of backfat thickness (18 mm). Precision feeding (PF) with the mixing of two diets was then simulated in comparison with conventional (CF) feeding with a single diet. Compared to CF, PF reduced protein and amino-acid intake and N excretion by 25%. At the same time, with PF, amino acid requirements were met for a higher percentage of sows, especially younger ones, and a lower percentage of sows, especially older ones, received excessive supplies.