Description par une approche méta-analytique des réponses d’ingestion et de croissance de porcelets sevrés soumis à une infection bactérienne digestive

An upset or disruption in animal health negatively affects voluntary feed intake and growth. The aim of this study was to describe, using meta-analysis, the impact of a gastrointestinal bacterial infection on the dynamic response of feed intake and growth in weaned piglets. The database consisted of 29 experiments published in peer-reviewed journals. It contained data on average daily feed intake and growth rate of piglets infected experimentally, mainly by Escherichia coli. The dynamic response was modelled using linear- or curvilinear-plateau functions. Correlation analyses between feed intake and growth made it possible to quantify the decrease in growth rate that was not directly due to the decrease in feed intake. The magnitude of the response following the challenge was greater for growth than for feed intake; the reduction in growth observed (expressed relative to the control treatment) was 85% whereas the reduction in feed intake was 15%. Feed intake of infected piglets returned to that measured in control piglets 40 days after the beginning of the infection. The return to higher growth rates took less time (15 days) but thegrowth rate of infected piglets was 8% lower than that of the control groups. The decrease in growth rate that was not explained by a decrease in feed intake was affected to the time of the measurements. These results are a step forward in quantifying the impact of health upsets in predictive growth models of pigs