Among various agricultural sectors, the livestock industry has a pivotal role in ensuring livelihood and food safety for the growing population and economies of countries. A changing climate, food scarcity for animals, increasing demand due to population burden, and low productive animals exert a negative impact on the livestock sector. These challenging factors and rising resistance to antibiotic-based growth promoters demand new and better approaches to improve the health, productivity of animals, and the sustainable growth of the livestock farming. Probiotics are living, non-pathogenic microbes, and their use is increasing nowadays as a substitute for antibiotic-based growth promoters. Probiotics exert a beneficial effect on the production, growth, nutrient intake, digestibility, and health of ruminants by regulating microbial homeostasis and by modifying ruminal fermentation.