Effects of generic ractopamine (Engain) on the growth performance, carcass characteristics, meat quality, and cutability of finishing barrows and gilts

The objectives were to test the effects of generic ractopamine (Engain; Zoetis Inc., Kalamazoo, MI) on growth, carcass characteristics, meat quality, and fat quality of finishing pigs. A total of 220 pigs were fed 0 mg/kg (CON) or 10 mg/ kg generic ractopamine (gRAC) for 28 d before slaughter. Barrows fed gRAC were 5.22 kg (4.13%) heavier (P < 0.0001) than CON barrows. Gilts fed gRAC were 5.44 kg (4.47%) heavier (P < 0.0001) than CON gilts. Barrows fed gRAC gained 0.21 kg/d (18.75%) more weight (P < 0.0001) than CON barrows. Gilts fed gRAC gained 0.20 kg/d (20%) more weight (P < 0.0001) than CON gilts. Generic RAC-fed barrows were 20% more (P < 0.0001) feed efficient than CON barrows. Generic RAC-fed gilts were 15.62% more feed efficient (P < 0.0001) than CON gilts. Longissimus-muscle area (11.9%) and loin depth (8.6%) were greater (P < 0.0001) in gRAC-fed barrows than CON barrows, whereas LM area (7.7%) and loin depth (6.4%) were greater (P < 0.001) in gRAC-fed gilts than CON gilts. Boneless cutting yields (1.77% units in barrows and 2.20% units in gilts) of gRAC-fed pigs were greater (P = 0.02) than cutting yields of CON. Feeding gRAC did not affect (P = 0.24) subjective LM quality characteristics. Fresh belly firmness was not (P = 0.66) affected by gRAC, but gRAC-fed gilts had greater (P = 0.01) proportions of all PUFA, particularly linoleic and linolenic acids, than CON gilts. Although shear force values did not differ (P = 0.24) between gRAC and CON barrows, gilts fed gRAC had 0.46 kg (13.7%) greater (P = 0.04) shear force values than CON gilts. Feeding 10 mg/kg of generic ractopamine to finishing pigs improved production efficiency and increased cutability but did not affect meat or fat quality.