The mucus layer plays an important role as an intermediate for the protection of the gut against acidic chyme, digestive enzymes, and pathogens; in addition, it acts as a lubricant and facilitator of nutrient transportation. Phytogenic compounds seem to promote intestinal mucus production. OBJECTIVES: The current study was conducted to investigate the effects of low and high levels of energy and amino acids in combination with turmeric, thyme, and cinnamon on chicken performance and expression of mucin 2 gene. METHODS: The eight experimental groups consisted of diluted and condensed diet with and without the addition of 5g/kg of each turmeric, thyme, and cinnamon to the diet. Chicken performance was recorded. Expression analysis of the mucin 2 gene was carried out by quantitative RT-PCR. RESULTS: Body weight gain, feed intake, FCR, and mortality rate were not affected by diets (p>0.05). A significant (p<0.05) reduction of the mucin 2 gene expression was observed in chickens fed by condensed diet; however, the expression increased by supplementation of turmeric, thyme, and cinnamon. CONCLUSIONS: These results, in addition to the function of herbs in increasing the activity of some enzymes which is possibly related to the mucin biological pathways, showed that the application of turmeric, thyme, and cinnamon could be useful in poultry diets. It appears that supplementation of turmeric, thyme, and cinnamon could increase mucin 2 gene expression in the small intestine, and this can improve intestinal digestive function and defense.

Background: Salmonellosis is one of the important diseases in the poultry industry, which also causes public health concerns.Objectives: We studied the effects of enrofloxacin and herbal medicines on growth performance, blood parameters, meat oxidation, and cecal microbial population in broilers challenged with Salmonella enterica serovar Typhimurium (ST).Methods: A total of 240 one-day-old (male) Ross 308 broiler chicks were randomly divided into 6 groups: negative and positive control, enrofloxacin, and three herbal medicines (A, B, and C) containing different proportions of cinnamon, thyme, licorice, and marjoram extracts with compounds of organic acids. The dosage of enrofloxacin and A, B, and C herbal medicines were 1, 1, 1, and 2 mL/L in drinking water, respectively, prescribed from days 16 to 21. On day 10, all groups except negative control were challenged with 1 mL suspension containing 1×107 CFU/mL ST. Performance traits were measured in intervals of 1-10, 11-24, 25-42, and 1-42 days. Blood parameters, meat oxidation, and cecal microbial population were measured on day 21.Results: Among the challenged groups, medicine C and enrofloxacin showed the lowest levels of Salmonella infection (P<0.05). Medicine B had a better effect on performance traits (P<0.05). Medicine A had the lowest amount of malondialdehyde in meat. Medicines A and B caused the lowest cholesterol and triglyceride concentration in serum (P<0.05).Conclusion: The above-mentioned herbal medicines can be used as beneficial additives in poultry nutrition to improve growth performance, reduce the Salmonella population in the gastrointestinal tract, and cholesterol, triglycerides, and meat oxidation.