Effects of Ractopamine and Carnitine in Diets Containing 5% Fat for Finishing Pigs

Purdue University 2002 Swine Research Report. The activation The pork industry is continually looking for means to increase pig growth rate, feed efficiency, and carcass lean percentage. To accomplish this, one option would be to explore increasing the amount of energy available for lean gain accretion. It is known that energy intake limits pig performance from 25 120 lb live weight. Therefore, by increasing dietary fat levels, energy intake and pig growth rate could be increased. However, the efficiency in which dietary fat is utilized for lean growth may decrease as dietary fat levels increase and as the pig matures. To compensate for this problem, it has been found that feeding carnitine may improve the utilization efficiency of dietary fat. Recently ractopamine (RAC) has been approved as a feed additive to increase lean growth rate, improve feed efficiency, and increase carcass lean percentage. Based on research conducted at Purdue University, the duration of response to ractopamine has decreased to four weeks. With a four-week duration response, it is important to maximize daily energy intakes to maximize the total response to ractopamine. As a result, it is thought that elevated fat diets with the inclusion of carnitine may enhance the lean accretion of pigs fed ractopamine by effectively increasing the available energy for lean tissue synthesis. The objective of this study is to incorporate ractopamine and carnitine into diets with elevated fat levels to determine the effects on growth rate, feed efficiency, and lean gain of finishing pigs.