The effect of ractopamine hydrochloride (Paylean(®)) on lean carcass yields and pork quality characteristics of heavy pigs fed normal and amino acid fortified diets.

Effects of ractopamine hydrochloride (RAC) on carcass parameters in heavy weight (133.24±8.07kg) finishing pigs (n=278) given amino acid fortified (AA) or 16% crude protein (CP) diets were evaluated. A total of seven experimental diets were formulated; RAC was added at 0, 5 and 20ppm to the 16% CP diets (CP0, CP5 and CP20, respectively) and at 0, 5, 10 and 20ppm to the AA fortified diets (AA0, AA5, AA10 and AA20, respectively). Carcass, tenderloin, and ham weights were heavier (P<0.05) for RAC AA diets vs. AA0. Loin weight was heavier (P<0.05) for AA20 vs. AA0 and CP20 vs. CP0. No differences (P>0.05) were observed for color or firmness scores. Carcass muscle score, ham weight and protein% were greater (P<0.05) for RAC diets. Moisture was greater (P<0.05) and fat was lower (P<0.05) for AA5 and AA20 vs. AA0 and CP5 and CP20 vs. CP0. Feeding RAC to late finishing swine increases carcass yields and protein% with lower fat% for pigs weighing up to 136kg.