| Scope and Method of Study: One experiment was conducted to determine the effects of ractopamine hydrochloride on growth performance, nutrient excretion, and gaseous emissions of finishing swine. During the first 3 phases, all pigs consumed a common control diet on an ad libitum basis. During phase 4, the control pigs received a finishing diet without ractopamine hydrochloride, and the treatment group received a diet containing 9 mg/kg of ractopamine hydrochloride on an ad libitum basis. The crude protein for the diet containing ractopamine hydrochloride was formulated to a minimum of 16%, while the control diet was formulated to requirements for swine during that stage of maturity and production.;Findings and Conclusions: Swine fed ractopamine hydrochloride had an increase in feed efficiency, higher rate of lean gain, and increased percentage of lean when compared to the control while consuming less total feed. Additionally, pigs fed ractopamine hydrochloride had a decrease in total nitrogen excretion by 4% and total phosphorus excretion by 2%. Furthermore, those pigs had a decrease in total methane emissions by 15% and total carbon dioxide equivalents, a measure of global warming potential, by 9%.;When ractopamine hydrochloride is included in the diet, growth performance is increased and maximized while decreasing the cost of gain. Additionally, reductions in nutrient excretion and gaseous emissions can be obtained by including ractopamine hydrochloride in the diet. These results suggest that including ractopamine hydrochloride in late finishing diets not only provides incentives economically, both on the hoof and rail, but decreases the environmental impact of large scale swine production. |
