Ractopamine (Paylean) Response in Heavy-Weight Finishing Pigs

The objective of this study was to investigate the effects of feeding diets with 10 ppm of ractopamine hydrochloride (RAC; Paylean 9G, Elanco Animal Health, Greenfield, IN) to heavy-weight pigs (final BW of 147 kg). Few studies have addressed the effects of RAC on performance and carcass traits at the finishing BW presented in this study. This study was carried out as a randomized complete block design with a 2 × 2 factorial arrangement of treatments, 1) sex (barrow or gilt) and 2) RAC inclusion (0 or 10 ppm), with a total of 128 pigs. Pigs were randomly assigned to pens of 4 and beginning BW was approximately 115 kg. After 28 d on test, pigs were slaughtered and a subset of pigs, totaling 64 pigs (2 pigs/pen), were selected for carcass characteristics and meat quality analysis. There were no sex × RAC interactions (P > 0.10). Final farm BW was increased (P = 0.003) by 3.3 kg, overall ADG was increased (P = 0.009) by 11.0%, and overall G:F was increased (P < 0.001) by 12.9% with RAC. The HCW was increased (P < 0.001) by 3.9 kg with RAC, and dressing percentage was increased (P = 0.001) to 76.04% from 75.06%. In the subset selected for carcass characteristics (n = 64), there was a trend of increasing (P = 0.08) lean cut yield. Ultimate pH was increased (P < 0.001) by 0.08 units, and drip loss was decreased (P = 0.011) to 4.31% from 5.59% with RAC. Feeding diets with 10 ppm RAC to pigs with ending BW of approximately 147 kg proved efficacious in improving BW, ADG, G:F, HCW, and dressing percentage without adversely affecting meat quality traits.