Reduction of Salmonella enterica serovar enteritidis colonization and invasion by an alfalfa diet during molt in Leghorn hens

Abstract

The standard method for molting to stimulate multiple egg-laying cycles in laying hens is feed deprivation. However, the physiological changes within hens caused by feed deprivation increase susceptibility of the hens to Salmonella enterica serovar Enteritidis (SE) infection. In an effort to develop an alternative method to induce molting without increasing susceptibility to SE, an alfalfa diet was compared with the standard molting method for the level of ovary regression and SE colonization. Hens over 50 wk of age were divided into 3 treatment groups (12 hens/group): nonmolting by normal feeding (NM), molting by feed deprivation (M), and molting by alfalfa diet (A). Individual hens on all treatments were challenged orally with 10(5) cfu of SE on the fourth day after feed changes and were analyzed for ovary weight and SE colonization or invasion in crop contents, cecal contents, liver, spleen, and ovary on the ninth day. In 3 of the 4 trials, there was a significant decrease in SE colonization of the crop between the alfalfa diet (A) and the feed deprived molt (M). In most of the 4 trials, there was a significant reduction in SE infected organs in birds fed the alfalfa diet (A) compared with birds undergoing feed deprived molt (M). Most of the trials showed no significant difference in overall SE between A and NM. Therefore, the results of this study suggest that an alfalfa diet has the potential to be used as an alternative method for forced molting, without increasing the incidence of SE in eggs and internal organs.

Supplementation with humic substances affects the innate immunity in layer hens in posfasting phase

“…Therefore, eggs produced in the early post-molt period present a higher risk of contamination for humans since the percentage of contaminated eggs is increased (29). Results reported in this study show that supplementing laying hens in the post-molt phase generated significant increases in IF, lysozyme activity and serum bactericidal activity during the early postmolt stage (Day 8 and 30), whereas the same supplementation in the mid post-molt stage (day 60) decreases IF markedly and does not present stimulatory effects on respiratory burst activity or lysozyme, however bacterial agglutination is stimulated at all measured times.…”

“…de huevos contaminados (29). Los resultados reportados en esta investigación demuestran que suplementando las gallinas ponedoras en la fase posmuda se generan incrementos significativos en el IF, actividad de la lisozima y actividad bactericida del suero durante la etapa temprana de la posmuda (día 8 y 30), mientras que con la misma suplementación en la etapa media de la posmuda (día 60) decrece marcadamente el IF, y no presenta efecto estimulante sobre la explosión respiratoria ni la actividad de la lisozima, no obstante la aglutinación bacteriana es estimulada en todos los tiempos medidos.…”

Salmonella Pathogenicity and Host Adaptation in Chicken-Associated Serovars

“…Several molt diets with fermentable substrate combinations have been screened in vitro and shown to support optimal avian cecal fermentation (396)(397)(398) and retain similar cecal microbial molecular profiles (397). In vivo application of some of these diets was shown to retain fermentation and GIT populations during molt while limiting the ability of S. Enteritidis to colonize the GIT and become invasive (255,270,392,399,400). The overall results of the studies demonstrate that there is a complex and important relationship between the microflora of the avian GIT and Salmonella, which is key to limiting the pathogen.…”

Animal Feed Production and Contamination by Foodborne Salmonella

“…Alternative approaches have usually involved the feeding of diets that nutritionally restrict the laying hen either by reducing intake via supplementation of minerals such as zinc or feeding high fi ber / low energy diets such as wheat middlings or alfalfa (Holt, 2003;Ricke, 2003a;Park et al, 2004). Several of these alternative diets have been shown to limit S. Enteritidis and induce molt when consumed by hens during infection studies (Seo et al, 2001;Moore et al, 2004;Ricke et al, 2004b;McReynolds et al, 2005;Woodward et al, 2005). In addition optimal microbial fermentation and resident microbial populations in the crop and ceca are generally retained in many of these alternative molting diets (Hume et al, 2003;Moore et al, 2004;Ricke et al, 2004a and b;McReynolds et al, 2005;Woodward et al, 2005).…”

“…Several of these alternative diets have been shown to limit S. Enteritidis and induce molt when consumed by hens during infection studies (Seo et al, 2001;Moore et al, 2004;Ricke et al, 2004b;McReynolds et al, 2005;Woodward et al, 2005). In addition optimal microbial fermentation and resident microbial populations in the crop and ceca are generally retained in many of these alternative molting diets (Hume et al, 2003;Moore et al, 2004;Ricke et al, 2004a and b;McReynolds et al, 2005;Woodward et al, 2005). When these alternative molting diets were compared with laying hens that have undergone feed withdrawal, similar egg production responses were observed (Biggs et al, 2003 and2004;Donalson et al, 2005;Landers et al, 2005a and b).…”