[en] Three experiments were performed to assess the ability of a Lactobacillus plantarum probiotic combined with a xylanase to reduce the effects of S. typhimurium infection in broiler chickens from 1- to 30- or 42-d-old. Chicks were challenged at 3-d-old with 108 or 105 cfu S. typhimurium/chick. Four diets were studied: a wheat-based diet (C+) supplemented with 0.1 g/kg xylanase (E), or 106 cfu/g or L. plantarum (P), or both (PE). Uninfected chicks fed the C diet were used as negative control (C-). Six or 8 chicks were housed per cage with 9 cages/treatment. Growth performance and feed conversion ratio (FCR) were recorded weekly. In experiment 1, bacterial enumeration in caeca was achieved using the fluorescent in situ hybridization technique. Salmonella enumeration was realized in excreta by microbiological cultures (Exp. 2 and 3). Nutrient digestibilities and AMEn were determined in experiment 3 from d 35 to d 39. Infection with S. typhimurium led to a significant decrease in the daily weight gain (DWG) by 23.6% to 32.8%, whereas FCR was increased by 1.0% to 19.7%. Chickens fed the PE diet showed significantly improved performance in comparison with C+ birds (DWG: +12.5% in Exp. 1; FCR: -2.1-8.6%), and in comparison with the P and E treatments (DWG: +6.3-8.3% in Exp. 1; FCR: -2.7-6.4%). In experiment 3, the FCR was significantly improved by 3% with the PE diet in comparison with C- chickens. The PE combination tended to restore a microflora similar to that of uninfected broilers, whereas the P and E diets had less of an effect on the profile of bacterial communities. At slaughter age, Salmonella contamination was reduced by 2.00 and 1.85 log cfu for the E and PE treatment, respectively. The PE diet significantly reduced the crude fat digestibility by 9.2%, in comparison with the C+ chickens. These results suggest that combination between L. plantarum and a xylanase as feed additive could be effective for reduction of detrimental effect following S. typhimurium infection of broilers.
Région wallonne : Direction générale des Technologies, de la Recherche et de l'Energie - DGTRE
Recherche d'un probiotique travaillant en synergie avec une hémicellulase en alimentation aviaire