Effect of distillers dried grains with solubles and ractopamine (Paylean) on quality and shelf-life of fresh pork and bacon

C. M. Leick,* C. L. Puls,* M. Ellis,* J. Killefer,* T. R. Carr,* S. M. Scramlin,* M. B. England,† A. M. Gaines,‡ B. F. Wolter,§ S. N. Carr,§ and F. K. McKeith*

*Department of Animal Sciences, University of Illinois, Urbana 61801; †Cargill Meat Solutions, Wichita, KS 67219; ‡The Maschhoffs, LLC, Carlyle, IL 62231; and §Elanco Animal Health, a Division of Eli Lilly and Company, Greenfield, IN 46140

Pigs (n = 240) were allotted in a 5 × 2 factorial arrangement with 5 levels of distillers dried grains with solubles (DDGS): 0, 15, 30, 45, and 60%, and 2 ractopamine (RAC) levels: 0 and 5 mg/kg. Four pigs per pen (2 barrows, 2 gilts) closest to pen mean BW were used for meat quality evaluation. Loins (n = 119) were evaluated for objective color; moisture and fat; subjective color, marbling, and firmness; and drip loss. Bellies (n = 119) were evaluated for weight, length, width, thickness, objective fat color, and firmness. Cured bellies were evaluated for pump yield, cook loss, and sliced bacon cook loss. Loin thiobarbituric acid reactive substances (TBARS) were evaluated on enhanced (salt and phosphate) boneless chops held in modified atmosphere (80% O2/20% CO2) packages for 0, 7, 14, and 21 d. Bacon TBARS were evaluated on sliced bacon held in vacuum packages for 0, 28, 56, and 84 d. Fat samples were collected from each jowl and belly and evaluated for fatty acid profile and iodine value (IV). Increasing DDGS decreased subjective marbling (P = 0.0134) and firmness (P = 0.0235), and increased drip loss (P = 0.0046). Distillers dried grains with solubles did not affect loin pH, subjective or objective color, percent moisture, or percent fat (P > 0.05). The RAC decreased subjective color (P = 0.0239), marbling (P = 0.0445), and a* (P = 0.0355). Increasing DDGS decreased belly weight (P = 0.0155), length (P = 0.0008), thickness (P = 0.0019), and firmness (P = 0.0054); decreased belly fat L* (P = 0.0818); and increased belly cook loss (P = 0.0890). Ractopamine did not affect any belly measurements, and there were no DDGS × RAC interactions (P > 0.05). Distillers dried grains with solubles did not affect loin TBARS at 0, 7, or 14 d. At 21 d, loin TBARS from 30, 45, and 60% DDGS groups were increased compared with 0 and 15% groups (P < 0.05). Ractopamine did not affect (P > 0.05) loin TBARS, and there were no (P > 0.05) DDGS × RAC interactions. Distillers dried grains with solubles and RAC did not affect bacon TBARS (P > 0.05). Increasing DDGS increased belly (P = 0.0207) and jowl (P < 0.0001) IV, and decreased MUFA:PUFA in belly (P < 0.0001) and jowl (P < 0.0001) fat. Ratio of SFA:unsaturated fatty acids decreased in jowl (P = 0.0002) and belly fat (P = 0.2815). Ractopamine did not affect fatty acid profiles or IV, and there were no DDGS × RAC interactions (P > 0.05). Results indicate that increased DDGS have minimal effects on loin quality, but decrease belly quality, bacon processing characteristics, and fat stability. Ractopamine does not negatively affect these characteristics and does not interact with DDGS.