  Salmonella Typhimurium oral challenge model in mature broilers: Bacteriological, immunological, and growth performance aspects.Marcq, Christopher  ; ; Szalo, Ioan Mihai et alin Poultry Science (2011), 90(1), 59-67 In this study, Salmonella enterica serovar Typhimurium challenge models were tested to identify the best conditions under which to perform the experimental infection of 3-wk-old broilers. Such a model ... [more ▼] In this study, Salmonella enterica serovar Typhimurium challenge models were tested to identify the best conditions under which to perform the experimental infection of 3-wk-old broilers. Such a model would be useful to study the efficiency of therapeutic treatments that could take place at the end of the grow-out period. Salmonella-free chicks were obtained from a breeder flock vaccinated with Salmonella. Intestinal maternal immunity was monitored by ELISA analyses at 2, 9, and 16 d of age. Data indicated that protection of maternal origin was not maintained over time and was drastically reduced at 9 d of age (P < 0.01). At 21 d of age, chickens were orally inoculated with Salmonella Typhimurium. The effects of the oral challenge dose (0, 3 x 10(3), 3 x 10(6), and 3 x 10(9) cfu/bird) and vancomycin pretreatment (no administration or 25 mg/bird) on intestinal immune responses, growth performance, and Salmonella colonization of chickens were investigated. After infection, the mucosal immune response was rapid, with increased (P < 0.01) anti-Salmonella Typhimurium IgA titers measured at 8 d postinfection in intestinal contents. A linear relationship (P < 0.05) existed between specific IgA levels in intestinal and cecal contents and the challenge dose inoculated. None of the challenge protocols caused mortality or clinical symptoms after infection. Nevertheless, the experimental infection induced a significant deterioration of growth performance. The pretreatment with 25 mg of vancomycin at 3 h before Salmonella inoculation was able to establish stable infection rates among the population of 3-wk-old infected chickens. Nevertheless, Salmonella shedding was not stable over the rearing period, and the bacteria seemed to be naturally eliminated from most birds at 22 d postinfection. This natural clearance of the gut, which was related, at least in part, to the intestinal immune response, should limit the usability of the created mature challenge model within 1 to 2 wk after inoculation. [less ▲] Detailed reference viewed: 223 (111 ULg)Efficiency of a Lactobacillus plantarum-xylanase combination on growth performances, microflora populations, and nutrient digestibilities of broilers infected with Salmonella TyphimuriumVandeplas, Sabrina ; Dubois Dauphin, Robin ; Thiry, Christophe et alin Poultry Science (2009), 88(8), 1643-1654 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 ... [more ▼] 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. [less ▲] Detailed reference viewed: 141 (50 ULg)Effects of feed supplementation with specific hen egg yolk antibody (immunoglobin Y) on Salmonella species cecal colonization and growth performances of challenged broiler chickens; Marcq, Christopher ; Thewis, André et alin Poultry Science (2009), 88(10), 2081-2092 Anti-Salmonella spp. egg yolk antibodies (IgY) simultaneously directed against Salmonella Enteritidis and Salmonella Typhimurium were tested to determine if their inclusion in feed decreased Salmonella ... [more ▼] Anti-Salmonella spp. egg yolk antibodies (IgY) simultaneously directed against Salmonella Enteritidis and Salmonella Typhimurium were tested to determine if their inclusion in feed decreased Salmonella spp. cecal colonization in experimentally infected broiler chickens. Egg yolk powder (EYP) was obtained by freeze-drying egg yolks containing anti-Salmonella spp. Immunoglobin Y was included in feed at 5 levels of concentration (0 to 5%). Feeds were formulated to similar nutrient levels and provided for ad libitum intake from d 1 to 28. Three days after initiation of feed treatments (d 4), chickens were co-challenged with equal numbers of Salmonella Enteritidis and Salmonella Typhimurium (2x10(6) cfu/bird). Cecal samples were recovered weekly over the experimental period (d 7 to 28) to enumerate Salmonella spp. The effect of anti-Salmonella spp. IgY feed supplementation on growth performance of infected chickens was also evaluated during the same period. In comparison with the positive control treatment (PC), treatments involving EYP (T1, T2, T3, T4, and T5), whether containing anti-Salmonella spp. IgY or not, significantly improved (P<0.05) the growth performance of challenged chickens, but without reaching the performance levels of nonchallenged chickens (NC1 and NC2). However, no link can be established between the enhancement in growth performance of challenged birds and their contamination levels by Salmonella because in-feed incorporation of EYP had no significant effect on cecal colonization by Salmonella. Furthermore, the comparison of the 5 anti-Salmonella spp. IgY concentration levels in feed did not reveal any anti-Salmonella spp. IgY concentration effect on growth performance and Salmonella cecal colonization. These results suggest that anti-Salmonella spp. IgY would undergo denaturation and degradation after their passage through the animal gastrointestinal tract and reveal that components of EYP other than specific antibodies have a beneficial effect on growth performance. [less ▲] Detailed reference viewed: 100 (36 ULg)Production Of Hen Egg Yolk Immunoglobulins Simultaneously Directed Against Salmonella Enteritidis And Salmonella Typhimurium In The Same Egg YolkChalghoumi, Raja ; Thewis, André ; Portetelle, Daniel et alin Poultry Science (2008), 87(1), 32-40 The present study was an attempt to raise hen egg yolk Ig (IgY) simultaneously directed against Salmonella Enteritidis (SE) and Salmonella Typhimurium (ST) in the same egg yolk. The immunopotentiating ... [more ▼] The present study was an attempt to raise hen egg yolk Ig (IgY) simultaneously directed against Salmonella Enteritidis (SE) and Salmonella Typhimurium (ST) in the same egg yolk. The immunopotentiating effect of 2 different adjuvants—Freund’s adjuvants (FA) and immunostimulating complexes matrix (IM)—on antibody response was also evaluated. Bacterial outer membrane proteins (OMP) were selected as target antigens. The ISA Brown hens, specific-Salmonella spp.-free status, divided into 6 groups were intramuscularly injected with a monocompound antigen preparation: SE-OMP (treatment SEFA or SE-IM) or ST-OMP (treatment ST-FA or ST-IM), or a combined antigen preparation: ¹⁄₂ SE-OMP and ¹⁄₂ STOMP (treatment SEST-FA or SEST-IM). Titers of antibodies in yolk were evaluated biweekly with ELISA. There was no antigen × adjuvant interaction on antibody titers. Anti-SE IgY titers in hens that received treatment SESTFA or SEST-IM were statistically similar (P > 0.05) as compared with those obtained from hens immunized with treatment SE-FA or SE-IM. Anti-ST IgY titers in hens immunized with treatment SEST-FA or SEST-IM were slightly lower than those of hens that received treatment ST-FA or ST-IM. The cross-reactivity of anti-SE IgY, induced by treatment SE-FA or SE-IM, with ST-OMP antigen and that of anti-ST IgY, induced by ST-FA or ST-IM, with SE-OMP antigen were arbitrarily assessed on d 43 and 155 by ELISA. The average cross-reactivity of anti-SE IgY with ST-OMP antigen was 71.7%. The average cross-reactivity of anti-ST IgY with SE-OMP antigen was 78.8%. In FA groups, antibody titers were found higher (P < 0.05) than those in IM groups. Furthermore, no extensive lesions or clinical abnormalities were detected in hens injected with FA. These findings showed the opportunity to raise IgY antibody against 2 Salmonella serovars in the same yolk and that FA was more efficient than IM in mediating antibody response. [less ▲] Detailed reference viewed: 85 (32 ULg)Comparison of monoamine concentrations in the brains of adult male and female Japanese quail.; ; et al in Poultry Science (1986), 65(7), 1413-20 A fluorometric assay measuring brain tissue concentrations of norepinephrine, dopamine, and serotonin has been validated for Japanese quail. Accuracy, precision, specificity, and parallelism were ... [more ▼] A fluorometric assay measuring brain tissue concentrations of norepinephrine, dopamine, and serotonin has been validated for Japanese quail. Accuracy, precision, specificity, and parallelism were determined. The sensitivity of the assays was 6 ng/tube, which allowed individual assay of 1 to 2 mg hypothalamic tissue. In Experiment 1, relatively large areas of brain from adult, reproductively active males and females were found to differ significantly in norepinephrine content in optic lobes and for dopamine in right telencephalon. A microdissection technique was used in Experiment 2 to sample small portions of hypothalamic tissue. Sex differences were observed for norepinephrine in the sections containing the lobus paraolfactorius and the preoptic, anterior, and medial hypothalamus. Differences in monoamine content were most apparent when smaller areas dissected by microdissection were analyzed. These results give evidence for sex differences in the monoamine content in specific areas of the brain. [less ▲] Detailed reference viewed: 4 (0 ULg) |
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