42 Environmental Impacts of Improving Forage Use Efficiency in Beef Cattle

Abstract

Abstract As population grows, so does the demand for high quality protein, and beef ranks among the greatest in terms of nutrient density per caloric intake. Maintaining the sustainability of beef cattle production systems has been one of the main priorities of researchers worldwide. Because the global demand for beef production is projected to increase, the contribution of beef production to greenhouse gas emissions will increase. One of the most useful tools available to researchers to reduce the carbon footprint of beef production is the selection for more feed efficient cattle. The use of residual feed intake as a criterion for selection has been demonstrated to have potential impact on the carbon footprint of beef systems, by reducing emissions intensity. Greenhouse gas emissions intensity involves the carbon footprint per unit of product (e.g., beef or milk produced) and it is the main metric to be considered when assessing the environmental impact of production systems. Great advances have been made in terms of improving the digestibility of forage resources. However, because of the impact that fiber digestion has on enteric methane production, these improvements in forage digestibility need to be considered in the context of emissions intensity. Advances in forage breeding such as the incorporation of brown mid-rib traits, have undoubtedly led to improvements in fiber digestion and animal productivity. Fewer studies have examined the impact of this technology on greenhouse gas emissions. A great opportunity exists to begin assessing the impact of new technologies such as the use or fibrolytic enzymes and prebiotics, with the potential of enhancing fiber digestibility. Global beef production will continue to rely heavily on high-forage diets for at least some segments of the production system. Assessing the impact of new technologies to enhance fiber digestion in the context of greenhouse gas emissions per unit of product will be essential to maintain the sustainability of beef production systems.