CASE STUDY: Environmental benefits of ractopamine use in United States finisher swine1, 2

Ractopamine (RAC) is a feed ingredient for use in finishing pigs that increases pork carcass muscle protein and improves production efficiency. A mathematical analysis of the environmental effects of increased rate of gain, improved feed efficiency, and increased carcass leanness was conducted, and for the analysis, it was assumed that RAC was implemented in all finishing pig diets in the United States at 5 or 10 mg/kg of diet, while producing the same amount of pork protein that is currently being produced. The average responses to 5 or 10 mg/kg RAC fed for the last 28 d before market included a 5.3 or 5.9% increase in carcass protein percentage, a 0.31 or 0.81% increase in carcass yield, a 12.0 or 10.9% increase in ADG, a 0.5 or 2.5% reduction in ADFI, and a 9.3 or 14.3% improvement in G:F, respectively, and approximately 3 fewer days to market. Using these assumptions, the current amount of pork could be produced with 5.3 or 6.3% fewer pigs. Because of improved efficiency and the reduction in animal numbers, 2.8 or 3.4 billion fewer kilograms (equivalent to 0.29 or 0.35 million hectares) of corn and 0.16 or 0.34 billion fewer kilograms (equivalent to 0.059 or 0.127 million hectares) of soybeans would be needed for pork production each year, respectively. This reduction in cropland acreage would lead to an annual reduction of 79 or 97.4 million kilograms of fertilizer, 0.8 or 1.05 million kilograms of pesticides (herbicides and insecticides), and 184 or 233 billion liters of water, respectively. In conclusion, the implementation of RAC in swine diets results in a reduced natural resource demand for pork production and improved environmental stewardship.