Roles of Essential Oils, Polyphenols, and Saponins of Medicinal Plants as Natural Additives and Anthelmintics in Ruminant Diets: A Systematic Review

SIMPLE SUMMARY: Ruminant nutritionists have been challenged to improve animal production efficiently but at the same time produce healthy and environment friendly ruminant-derived food products. Recent studies on utilizing essential oils, polyphenols, and saponins of herbal plants show that these bioactive components can play important roles as alternative natural dietary additives and anthelmintics, in order to replace growth-promoting antibiotic and chemical anthelmintic treatments. Since the prohibition of using growth-promoting antibiotics and chemical anthelmintics, the global market has emphasized the use of natural feed additives and anthelmintics as alternatives for ruminants. This article presents the potentials and problems of using plant-based bioactive compounds for sustainable ruminant diets to support food safety and food security. ABSTRACT: Public awareness on health and safety issues in using antibiotics for livestock production has led many countries to ban the use of all growth-promoting antibiotics (GPA) for livestock feeding. The ban on the utilization of antibiotics in livestock, on the other hand, is an opportunity for researchers and livestock practitioners to develop alternative feed additives that are safe for both livestock and the consumers of animal derived foods. Many feed additives were developed from a number of plants that contain secondary metabolites, such as essential oils, polyphenols, and saponins. These secondary metabolites are extracted from various parts of many types of plants for their uses as feed additives and anthelmintics. Recent investigations on using essential oils, polyphenols, and saponins as dietary additives and anthelmintics demonstrate that they can increase not only the production and health of ruminants but also ensure the safety of the resulting foods. There are many publications on the advantageous impacts of dietary plant bioactive components on ruminants; however, a comprehensive review on individual bioactive constituents of each plant secondary metabolites along with their beneficial effects as feed additives and anthelmintics on ruminants is highly required. This current study reviewed the individual bioactive components of different plant secondary metabolites and their functions as additives and anthelmintics to improve ruminant production and health, with respect to safety, affordability and efficiency, using a systematic review procedure.