Since the use of antibiotics in animal feeds has been banned, researches on alternative natural products that modulate ruminal fermentation have been intensified. Natural compounds such as plant extracts have been considered to be replaced antibiotics as safe and sustainable alternatives. Plant extracts especially essential oils and saponins have strong antimicrobial, antiparasitic, antiprotozoal and anti-inflammatory properties. These natural compounds have been modulated the ruminal fermentation to improve nutrient utilization in ruminants. Therefore, the purpose of this review is to provide an overview of the literature surrounding use of herbal plants as feed additives in ruminant nutrition. تفاصيل المقالة