Narasin sodium salt is primarily used as an anticoccidial agent in poultry farming. It is added to animal feed to prevent and control coccidiosis, a parasitic disease caused by protozoa that affects the intestinal tract of birds. By inhibiting the growth and reproduction of coccidia, it helps improve the health and growth performance of poultry, leading to better feed efficiency and reduced economic losses in the industry. It is also used in swine production as a feed additive to promote growth and improve feed efficiency. Additionally, it is sometimes used in combination with other feed additives to enhance its efficacy and broaden its spectrum of activity against various strains of coccidia. Its application is strictly regulated to ensure safety and prevent resistance development in the parasites.