Dietary Bacillus subtilis B2A strain in laying hens challenged with Salmonella gallinarum: effects on egg production, egg quality, blood haptoglobin and targeted intestinal Salmonella shedding

Abstract

A total of 240 Hy-Line 40-week-old Salmonella-free layers were assigned to 5 dietary treatments composed of 12 replications, with 4 laying hens per replications in a 5-week experiment trial on laying hens challenged with Salmonella gallinarum. Dietary treatment comprised: (1) NC, basal diet; (2) PC, NC + oral S. gallinarum administration; (3) B8, PC + 0.1% Bacillus subtilis (10 8 cfu/g); (4) B9, PC + 0.1% B. subtilis (10 9 cfu/g) and (5) B10, PC + 0.1% B. subtilis (10 10 cfu/g). B. subtilis groups reduced the population of S. gallinarum in both large intestine and excreta compared with PC laying hens. The population of S. gallinarum in challenged laying hens fed B. subtilis was significantly lower in small intestine, large intestine and excreta. In the small intestine, Lactobacillus population was higher in B10 compared with PC. Addition of B. subtilis improved eggshell thickness. Egg shell strength showed an improvement in week 5 and it was higher in B9 and B10 compared with PC. Haptoglobin concentration was higher in the PC group compared with other groups. In conclusion, diets supplemented with B. subtilis as a novel anti-salmonella bacteria show potential for decreasing S. gallinarium in the intestinal tract and improving egg gravity, eggshell strength and eggshell quality during the laying period.ARTICLE HISTORY

The Effect of Dietary Probiotic Supplementation on Egg Weight in Laying Hens: A Meta–Analysis Study

“…While Mahdavi et al (2005) showed the effect on albumin quality, Xu et al (2006) proved increasing egg weight. On the other hand, Sobczak and Kozlowski (2015) and Hosseindoust et al (2018) did not find the results statistically significant. These results show that using probiotics is effective on egg weight and other traits but this could not be clearly demonstrated.…”

“…The keywords searched according to the study protocol were laying hens, probiotic, B. Subtilis and egg weight. In this study, 37 studies were examined and 8 studies (Mahdavi et al 2005, Xu et al 2006, Zhang et al 2012, Amani et al 2013, Sobczak and Kozłowski 2015, Forte et al 2016b, Mazanko et al 2017, Hosseindoust et al 2018) that met the above conditions were selected and subjected to metaanalysis. In these studies, the difference between experimental and control groups was examined and none of them were statistically significant.…”

The targeted anti-Salmonella bacteriophage attenuated the inflammatory response of laying hens challenged with Salmonella Gallinarum

“…Bacteriophages are new types of animal antipathogen agents, which increase growth performance and improve animal health ( Adhikari et al, 2017 ; Hosseindoust et al, 2017 , 2018 ; Lee et al, 2021 ). In the current study, the preventive role of bacteriophage on gene expression of TLR4 and inflammatory cytokines were relatively higher in the jejunum rather than in the liver and muscle.…”

“…Outbreaks of S. Gallinarum have frequently occurred in laying hen farms with considerable economic losses ( Seo et al, 2019 ). S. Gallinarum is a bird-specific pathogen with systemic infection initiating from the intestine and gradually infecting the other organs ( Hosseindoust et al, 2018 ). The laying hen immune response to control S. Gallinarum infection is not clearly understood, however, it has already been known that the enterocytes, cecal tonsils, and Peyer's patches are the first target of S. Gallinarum ( Setta et al, 2012 ).…”

“…This is an important issue in breeder farms through transferring Salmonella to their progeny by polluted eggs. The use of nonantibiotic factors such as probiotics ( Hosseindoust et al, 2018 ) and bacteriophage ( Adhikari et al, 2017 ; Choi et al, 2020 ; Lee et al, 2021 ) have shown preventive and therapeutic effects on Salmonella infection control through the gastrointestinal tract. The specificity of bacteriophages in omitting the targeted pathogens increases its importance to be used in challenged laying hens.…”