Growth performance, intestinal histomorphology, gut microflora and ghrelin gene expression analysis of broiler by supplementing natural growth promoters: A nutrigenomics approach

In an epoch of escalating number of antibiotic-resistance bacteria, there is a dire need to develop efficient and novel feeding strategies for animal nutrition as alternatives to antibiotics. Here, implicating nutrigenomic approach, phytobiotics and organic acids were used to evaluate ghrelin gene expression levels, gut microflora composition, performance parameters and intestinal histomorphological changes in broiler chickens. One-day-old chicks (n = 315) were reared for 42 days and distributed randomly into five experimental groups; each with three replicates (21 birds per replicate). Experimental groups were control: basal diet only, antimicrobial growth promoter: 40 g/metric ton of basal diet (virginiamycin), organic acids: 4 kg/metric ton of basal diet, phytobiotics: 3 kg/metric ton of basal diet, combination: 7 kg/metric ton of basal diet (organic acids 4 kg and phytobiotics 3 kg metric ton of feed). Growth performance, histological and ghrelin gene expression analysis were executed on 21 and 42 days while, quantitative bacterial analysis of cecum and ileum was performed on day 42. Increased feed intake and body weight (p < 0.05) were noticed in phytobiotics group. Addition of phytobiotics significantly improved (p < 0.05) villus height and ratio of villus height/crypt depth in ileum, jejunum, and duodenum and down-regulated ghrelin gene expression levels. Total coliform and Escherichia coli in cecal and ileal digesta were decreased significantly (p < 0.05) in organic acids group. Correlation analysis revealed Lactobacillus spp. were positively correlated to villus height/crypt depth ration in duodenum. The findings indicated the importance of gene-nutrient-microbiota interactions based on nutrigenomics approach. Hence, phytobiotics and organic acids might be suitable alternatives to antibiotics for improved performance and immunity, along with healthier meat production in poultry.