The dietary inclusion of plant extracts improves growth performance, gut microbiota and blood parameters of broilers: a meta-analysis

A growing body of literature examined the effects of including plant extracts in poultry diets. Most of these studies have focused on changes in growth performance (weight gain, feed intake, feed conversion ratio, etc.) resulting from dietary inclusion of plant extracts. The effects of plant nutraceutical extract on broiler chickens have been reported with different results. Thus, this meta-analysis aimed to gauge the effect of plant nutraceutical extract on broiler chickens’ growth, intestinal components and blood characteristics. Two publicly available databases were searched to find studies evaluating dietary plant nutraceutical extracts on broiler chickens. The study selection was based on predefined criteria and two publicly available databases, ScienceDirect and Google Scholar, were utilised for execution. The analysis comprised 24 studies involving 60 treatment groups eligible for analysis in RevMan software. The results showed that plant nutraceutical extract inclusion significantly reduced feed conversion ratio (p < .05), leading to improved production performance. The pathogenic gut microbiota was also influenced by a significant reduction in Salmonella and Escherichia coli counts (p < .05) in the broilers. Plant nutraceutical-based diets also significantly increased the Lactobacillus and Bifidobacteria (p < .01) in broiler chickens. In addition, blood characteristics had significantly higher haemoglobin and globulin or total cholesterol, whereas triglycerides had a significantly lower impact than the control group. Consequently, plant extracts have the potential to serve as natural alternatives to antibiotics to reduce the risk of antimicrobial resistance and support sustainable poultry production. However, application of latest technologies is required to attain its full potential.