The impacts of using rosemary ( <i>Rosmarinus officinalis</i> Linn.) on oxidative stress, performance, serum biochemistry, microbial community, and immunity of poultry

Abstract Due to the emerging of drug resistance and presence of tissue residues, searching for natural feed alternatives in livestock production become an urgent need. Phytochemicals are now widely used in poultry farming as feed additives with successful results. Rosemary ( Rosmarinus officinalis Linn.) is a medicinal herb that has many beneficial bioactive components such as flavonoids, phenols, and others. Dry leaves, powder, oil, and extract forms of rosemary have been applied in poultry field and processing plants. It showed a powerful antioxidant capacity, alleviated oxidative damage, and balanced the redox homeostasis of serum in the treated birds. Improving the zootechnical parameters such as the production performances of broilers and layers as well as the carcass traits were also observed in rosemary treated birds flocks. Moreover, the hypolipidemic effect of rosemary was reported due to regulation of lipid metabolism of liver and reduction of liver and kidney toxicity. The antimicrobial, anti-inflammatory, and immuno-stimulant impacts of rosemary were documented. Thus, this review article was planned to investigate the different impacts of using rosemary on oxidative stress, performance, serum biochemistry, microbial community, and immunity of poultry.