Date of this Version
Forty pigs (66.6 lb) were used in a 14-week 4-phase regime study conducted to evaluate the effect of feeding varying concentrations of DDGS to growing-finishing pigs formulated on a standardized ileal digestibility (SID) lysine (lys) basis, DDGS withdrawal at the last feeding phase, and ractopamine (RAC) supplementation 4 weeks prior to harvesting on carcass quality, and color stability and sensory characteristics of longissimus muscle (LM) of finishing pigs. Treatments consisted in 0, 15, or 40% dietary DDGS inclusion supplemented with or without RAC (4.5 ppm) 4 weeks prior harvesting. Final body weight, hot carcass weight, and dressing percentage were not affected by dietary DDGS inclusion, withdrawal or RAC supplementation (P > 0.10). Color characteristics were not affected by dietary DDGS inclusion or withdrawal (P > 0.10); however, dietary RAC supplementation reduced a* and b* at days 0 and 7 (P > 0.10). Total polyunsaturated fatty (TPUFA) acids increased and total saturated fatty acids (TSFA) were decreased in response to increased dietary DDGS inclusion (P < 0.01); however, DDGS withdrawal partially alleviated these changes in fatty acid composition by increasing TSFA and reducing TPUFA (P < 0.01). The inclusion of RAC decreased TSFA and increased total monounsaturated fatty acids concentration (P = 0.03 and 0.04, respectively). Sensory characteristics were not affected by dietary RAC, DDGS inclusion or DDGS withdrawal (P > 0.10). The results of this investigation suggest that dietary RAC, DDGS inclusion or DDGS withdrawal did not affect carcass quality as evaluated by color, chemical composition, and sensory characteristics of LM of growing-finishing pigs. Increasing the concentration of dietary DDGS altered the fatty acid profile of backfat of pigs by decreasing saturated and increasing unsaturated fatty acids. However, withdrawing DDGS, 4 weeks prior to harvesting partially alleviated the increase in PUFA, and consequently the “soft pork” problems associated with the use of DDGS.