The utility of antimicrobial agents as a preventive measure has been questioned, given extensive documentation of the evolution of antimicrobial resistance among pathogenic bacteria. Non-antibiotic feed additives (probiotics, prebiotics, essential oils and organic acids) are being considered to fill this gap and already a few farmers in the country are using them with good results. The present study enable us to understand and compare the beneficial effects of non-antibiotic feed additives on salmonella enterica colonization and changes in intestinal morphology.
This study is designed to evaluate the effect of non-antibiotic feed additives on salmonella enterica serovar enteritidis colonization in intestine of broilers chickens and compare the intestinal morphology between normal healthy, non-antibiotic feed additives supplemented and salmonella challenged broiler chickens.
A total of 125 commercial day-old broiler chicks were procured from the local market. The chicks were divided into six groups A (Basal diet, negative control group), B (Challenge + Basal diet, positive control group), C (probiotic + Challenge + Basal diet), D (prebiotic + Challenge + Basal diet), E (essential oils + Challenge + Basal diet) and F (organic acids + Challenge + Basal diet) with 20 chicks in each group and given separate treatments.
Two separate experiments were carried out for salmonella recovery from cecal tonsils and intestinal pathomorphic evaluation. Villus length, villus width, villus surface area and crypt depth were measured by micrometery. The collected data from both experiments was analyzed using the statistical technique of comparing more than two groups i.e. Analysis of variance (ANOVA) through SPSS 16.0.
Summary
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There was an overall increase in all the parameters of intestinal morphometric analysis for all the treatment groups except for the control negative group which showed lowest values. Maximum villus height of 1794.2±63.96 μm in duodenum was achieved by group E, which was given essential oils. Whereas maximum villus surface area index of 1662.6±389.16 mm2 was recorded in group D, which was treated with prebiotics. Maximum villus height of 940.35±23.96 μm and surface area index of 568.92±36.27 mm2 in ileum mucosa was recorded in group D, treated with prebiotic. . Recoverable salmonella was most reduced by probiotics and organic acids.
Final results show that there is an overall increase in histological parameters of the mucosa of duodenum and ileum in the groups fed non-antibiotics feed additives as compared with control groups. Prebiotics showed the maximum positive effects in histological parameters whereas probiotics showed maximum positive effect for decreased recoverable salmonella count. Hence this study suggests that a combination of non-antibiotic feed additives will be beneficial for the intestinal health of broiler chickens but there is a need for more research on combinations of non-antibiotic feed additives.