The Effects of Ractopamine Hydrochloride (Paylean) on Efficiency, Carcass Composition, Carcass Quality and Fat Quality in High Lean Growth Pigs

122 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2003.Experiments were conducted to evaluate the effects of ractopamine hydrochloride (PayleanRTM) (RAC) on efficiency, carcass composition, carcass quality and fat quality in high lean growth pigs. The first study evaluated the effect of RAC on growth performance and carcass characteristics of late finishing swine. Feed efficiency, average daily gain and dressing percentage were all improved (P < 0.05) with the inclusion of RAC. In addition, minimal to no effects were observed for carcass quality characteristics from pigs fed RAC. The effect of RAC on lean carcass yields and pork quality characteristics were also examined. Results indicate that RAC had positive effects on carcass cutting yields and had little effect on pork palatability attributes of flavor and juiciness while reducing (P < 0.05) tenderness. Another study evaluated the effect of RAC on lean carcass yields and pork quality characteristics of heavy pigs fed normal and amino acid fortified diets. Results from this study indicate that RAC improved carcass characteristics and cutting yields when fed to heavy weight swine using both crude protein and amino acid fortified diets with no adverse effects on carcass linear traits, carcass cutting yields or carcass quality. The final study investigated the effects of different energy sources and RAC on carcass and fat quality in late finishing pigs. Feed efficiency was improved (P 0.05) on subjective fat or color and subjective or Minolta L* loin color as well as marbling or firmness. Barley fed pigs had whiter (P < 0.05) objective fat color compared to pigs fed wheat. Minimal to no differences were observed for fatty acid profiles and iodine values for both energy source and RAC inclusion. In conclusion, results from these studies show that RAC positively affects the feed efficiency and average daily gain of pigs during the late finishing period with little to no deleterious effects on carcass, pork or fat quality. In addition pigs fed the corn and wheat diets were more efficient than those pigs fed the barley diets. However, little to no differences in average daily gain, carcass, pork or fat quality were observed for pigs fed different energy sources during the finishing period either with or without RAC.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD