Feeding and Nutritional Strategies to Reduce Methane Emissionfrom Large Ruminants: Review

Livestock are considered as a main source of GHGs emission by contributing approximately 9% of the total global emission and a major concern for global warming. Domestic animals account approximately 94% of the total global emissions of animals from these large ruminants (dairy and beef cattle) produce 30% and 35% of the livestock sectors’ emissions. Most methane (CH4) that is emitted from livestock originates in the forestomach, also called the rumen, of ruminants. Minimizing amount of methane that comes from rumination can improve production efficiency of livestock and is environmentally a sound practice. The emission rate can be minimized by handling proper feeding and nutritional management strategies, which can reduce excretion of GHG during ruminant digestion process. Dietary manipulation, type of carbohydrates animals fed, forage quality and maturity, management of pasture land, nutrient composition of diet and feed intake, feeding frequency, fat supplementation, and inclusion of feed additives such as saponins, tannins and essential oils are among the best feeding and nutritional management strategies to minimize amount of methane produced during rumination. The aim of this review was to investigate feeding and nutritional management strategies used to reduce methane production from ruminants in general and large ruminants in particular.