The health of broiler chickens’ intestines when using a phytogenic composition in their diet
Abstract
Relevance. The reduction in the use of feed antibiotics in poultry farming necessitates the development and study of alternative feed additives that positively affect gut health. Such additives include phytobiotics, which exhibit anti-inflammatory, antioxidant, antibacterial, and immunomodulatory properties. To identify the effect of different variants of a phytobiotic composition on gut health, an experiment was conducted on broiler chickens. Methods. Three groups were formed, two of which were fed two variants of the phytobiotic composition with different ratios of chicory extract (40/35%), St. John’s wort (10/5%), safflower leuzea (35/40%), and creeping thyme (15/20%) in their diets. The impact on gut health was assessed through morphological characteristics of the cecum tissues, relative expression of genes related to resistance, and levels of opportunistic pathogenic microbiota. Results. The results indicated a decrease in the expression of genes associated with inflammation and pathogen resistance in the gut tissues of the experimental groups: AvBD9 activity decreased 7.0-fold (p ≤ 0.05), AvBD10 by 12.7 to 140.0-fold (p ≤ 0.01), IL8L2 by 154.0-fold (p ≤ 0.01), and IRF7 by 47.0-fold (p ≤ 0.05). Histological studies showed reductions in epithelial height by 24.7 to 49.1% (p ≤ 0.001) and submucosal thickness by 2.8-2.9 times (p ≤ 0.001), an increase in crypt depth by 80.5% (p ≤ 0.001), muscularis mucosa thickness by 6.5% (p ≤ 0.05), and muscular layer thickness by 14.8% (p ≤ 0.001). No signs of degradation or suppression of epithelial cells were observed in the treated groups compared to control. Escherichia coli strains harboring virulence factors such as ybtA, iroE, fliA, epaQ, ycbV, ykgK/ecpR, fliP, espL4, cheB, stgC, among others, accounted for 11.98% of the cecal microbiome in the control group, whereas their abundance decreased to 3.74% in the 2nd experimental group and to 0.71% in the 3rd experimental group (p ≤ 0.05). These findings allow considering the developed phytogenic compositions as feed biopreparations aimed at improving gut health in broiler chickens.