Journal of Animal Science, Vol 72, Issue 12 3152-3162, Copyright © 1994 by American Society of Animal Science

JOURNAL ARTICLE

The impact of ractopamine, energy intake, and dietary fat on finisher pig growth performance and carcass merit

N. H. Williams, T. R. Cline, A. P. Schinckel and D. J. Jones
Department of Animal Sciences, Purdue University, West Lafayette, IN 47907.

An experiment was conducted to determine the effect of ractopamine, energy intake, dietary fat level, and sex on performance and carcass composition in finishing pigs. Three hundred six barrows and gilts were used in a factorial arrangement of treatments replicated over three seasons. Treatments consisted of two ractopamine levels (0 vs 44.7 mg/d), two sexes (barrows and gilts), two levels of fat addition (0 vs 5% added fat), and four energy intake levels (8.3, 8.9, 9.5, and 10.1 Mcal of ME/d for barrows and 7.7, 8.3, 8.9, and 9.5 Mcal of ME/d for gilts). Diets were formulated to maintain an equal lysine (28.5 g/d) intake at each feeding level through cornstarch dilution of the basal (7.7 Mcal of ME/d) diets. Pigs were fed daily based on a standard feed intake curve and prior weekly body weights. At slaughter (104 kg), carcass measurements and TOBEC HA-1 scanner measurements were recorded. Dietary fat addition improved live weight and lean efficiency (grams of carcass lean gain/kilogram of feed, P < .05). Dietary fat addition did not affect growth rate or carcass composition. Increasing energy intake resulted in a linear increase in average daily gain for both barrows and gilts (P < .01). Dietary ractopamine influenced the response of lean tissue accretion, lean tissue accretion efficiency, and fat tissue accretion to energy intake. Pigs with no added ractopamine demonstrated increased lean tissue accretion and improved efficiency and decreased fat tissue accretion with increasing energy intake (up to 9.5 Mcal of ME intake for barrows and 8.9 Mcal of ME intake for gilts). In contrast, pigs with added ractopamine did not respond to increasing energy intake and demonstrated increased fat tissue accretion with increasing energy intake. The response to ractopamine for growth was greatest from d 6 to 22 on test or during the test gain period of 7 to 18 kg. After d 22, the response of ractopamine declined linearly. These results indicate that ractopamine increases growth rapidly at the onset of feeding until a plateau is reached, after which there is a linear decline in growth response.

This article has been cited by other articles:

				N. Z. Frantz, M. D. Tokach, R. D. Goodband, S. S. Dritz, J. M. DeRouchey, J. L. Nelssen, and C. L. Jones The Optimal Standardized Ileal Digestible Lysine and Total Sulfur Amino Acid Requirement for Finishing Pigs Fed Ractopamine Hydrochloride Professional Animal Scientist, April 1, 2009; 25(2): 161 - 168. [Abstract] [PDF]

				R. Poletto, M. H. Rostagno, B. T. Richert, and J. N. Marchant-Forde Effects of a "step-up" ractopamine feeding program, sex, and social rank on growth performance, hoof lesions, and Enterobacteriaceae shedding in finishing pigs J Anim Sci, January 1, 2009; 87(1): 304 - 313. [Abstract] [Full Text] [PDF]

				J. M. Gonzalez, R. D. Dijkhuis, D. D. Johnson, J. N. Carter, and S. E. Johnson Differential response of cull cow muscles to the hypertrophic actions of ractopamine-hydrogen chloride J Anim Sci, December 1, 2008; 86(12): 3568 - 3574. [Abstract] [Full Text] [PDF]

				D. M. Fernandez-Duenas, A. J. Myers, S. M. Scramlin, C. W. Parks, S. N. Carr, J. Killefer, and F. K. McKeith Carcass, meat quality, and sensory characteristics of heavy body weight pigs fed ractopamine hydrochloride (Paylean) J Anim Sci, December 1, 2008; 86(12): 3544 - 3550. [Abstract] [Full Text] [PDF]

				J. N. Marchant-Forde, D. C. Lay Jr., R. M. Marchant-Forde, K. A. McMunn, and B. T. Richert The effects of R-salbutamol on behavior and physiology of finishing pigs J Anim Sci, November 1, 2008; 86(11): 3110 - 3124. [Abstract] [Full Text] [PDF]

				J. K. Apple, C. V. Maxwell, B. R. Kutz, L. K. Rakes, J. T. Sawyer, Z. B. Johnson, T. A. Armstrong, S. N. Carr, and P. D. Matzat Interactive effect of ractopamine and dietary fat source on pork quality characteristics of fresh pork chops during simulated retail display J Anim Sci, October 1, 2008; 86(10): 2711 - 2722. [Abstract] [Full Text] [PDF]

				C. S. Abney, J. T. Vasconcelos, J. P. McMeniman, S. A. Keyser, K. R. Wilson, G. J. Vogel, and M. L. Galyean Effects of ractopamine hydrochloride on performance, rate and variation in feed intake, and acid-base balance in feedlot cattle J Anim Sci, November 1, 2007; 85(11): 3090 - 3098. [Abstract] [Full Text] [PDF]

				J. M. Gonzalez, J. N. Carter, D. D. Johnson, S. E. Ouellette, and S. E. Johnson Effect of ractopamine-hydrochloride and trenbolone acetate on longissimus muscle fiber area, diameter, and satellite cell numbers in cull beef cows J Anim Sci, August 1, 2007; 85(8): 1893 - 1901. [Abstract] [Full Text] [PDF]

				S. L. Gruber, J. D. Tatum, T. E. Engle, M. A. Mitchell, S. B. Laudert, A. L. Schroeder, and W. J. Platter Effects of ractopamine supplementation on growth performance and carcass characteristics of feedlot steers differing in biological type J Anim Sci, July 1, 2007; 85(7): 1809 - 1815. [Abstract] [Full Text] [PDF]

				T. E. Weber, B. T. Richert, M. A. Belury, Y. Gu, K. Enright, and A. P. Schinckel Evaluation of the effects of dietary fat, conjugated linoleic acid, and ractopamine on growth performance, pork quality, and fatty acid profiles in genetically lean gilts J Anim Sci, March 1, 2006; 84(3): 720 - 732. [Abstract] [Full Text] [PDF]

				T. A. Armstrong, D. J. Ivers, J. R. Wagner, D. B. Anderson, W. C. Weldon, and E. P. Berg The effect of dietary ractopamine concentration and duration of feeding on growth performance, carcass characteristics, and meat quality of finishing pigs J Anim Sci, November 1, 2004; 82(11): 3245 - 3253. [Abstract] [Full Text] [PDF]

				J. K. Apple, C. V. Maxwell, D. C. Brown, K. G. Friesen, R. E. Musser, Z. B. Johnson, and T. A. Armstrong Effects of dietary lysine and energy density on performance and carcass characteristics of finishing pigs fed ractopamine J Anim Sci, November 1, 2004; 82(11): 3277 - 3287. [Abstract] [Full Text] [PDF]

				K. W. Ssu, M. C. Brumm, and P. S. Miller Effect of feather meal on barrow performance J Anim Sci, September 1, 2004; 82(9): 2588 - 2595. [Abstract] [Full Text] [PDF]

				M. T. See, T. A. Armstrong, and W. C. Weldon Effect of a ractopamine feeding program on growth performance and carcass composition in finishing pigs J Anim Sci, August 1, 2004; 82(8): 2474 - 2480. [Abstract] [Full Text] [PDF]

				A. P. Schinckel, N. Li, B. T. Richert, P. V. Preckel, and M. E. Einstein Development of a model to describe the compositional growth and dietary lysine requirements of pigs fed ractopamine J Anim Sci, May 1, 2003; 81(5): 1106 - 1119. [Abstract] [Full Text] [PDF]

				J. N. Marchant-Forde, D. C. Lay Jr., E. A. Pajor, B. T. Richert, and A. P. Schinckel The effects of ractopamine on the behavior and physiology of finishing pigs J Anim Sci, February 1, 2003; 81(2): 416 - 422. [Abstract] [Full Text] [PDF]

				A. P. Schinckel, C. T. Herr, B. T. Richert, J. C. Forrest, and M. E. Einstein Ractopamine treatment biases in the prediction of pork carcass composition J Anim Sci, January 1, 2003; 81(1): 16 - 28. [Abstract] [Full Text] [PDF]