|Mccollum, F. Ted|
Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 11/30/2008
Publication Date: 3/16/2009
Citation: MacDonald, J.C., Jenkins, K.H., Buttrey, E., Lewis, J.B., Smith, S.B., Miller, R.K., Lawrence, T.E., McCollum, F., Cole, N.A. 2009. 35% corn wet distiller's grains plus solubles in steam-flaked and dry-rolled corn finishing diets: Effects on fatty acids, sensory attributes, and shelf life of loins [abstract]. In: Abstracts of 2009 Midwest Section of American Dairy Science Association Conference, March 16-18, 2009, Des Moines, Iowa. Abstract No. 271, p. 85-86.
Technical Abstract: Fifty-four crossbred steers were fed dry-rolled corn (DRC) or steam-flaked corn (SFC) based finishing rations with or without 35% wet distiller's grain plus solubles (WDGS) to determine effects of corn processing method and WDGS inclusion on marbling attributes, sensory attributes, and shelf-life of beef loins. Subcutaneous adipose tissue was collected and analyzed for enzyme activity and cellularity. One loin per steer was purchased and cut into 2.54 cm steaks. One steak was frozen and analyzed for fatty acid composition. A second steak was vacuum packaged and aged for 14-d prior to freezing for sensory analysis using a trained taste panel and SpectrumË procedures. Five steaks were individually packaged and randomly assigned for 0, 1, 3, 5, or 7-d of storage in simulated supermarket conditions and analyzed for thiobarbituric acid reactive substances (TBARS) and color. No differences in NADP-malate dehydrogenas, 6-phosphofructokinase activities, or intramuscular adipocyte volume or diameter due to WDGS inclusion were detected (P > 0.40). The monounsaturated:saturated ratio of fatty acids from longissimus muscle was strongly decreased by WDGS (P < 0.01), likely due to a reduction in '9 desaturase enzyme activity as indicated by a depression in the ratio of 16:1/18:0 fatty acids (P = 0.08). Total fat content of steaks tended to increase with WDGS inclusion (P = 0.09). Differences in sensory attributes due to WDGS inclusion were statistically significant, but minimal in magnitude. Inclusion of WDGS into finishing diets increased lipid oxidation after five days of storage (P = 0.01) as measured by TBARS which resulted in steaks with reduced L* scores (P < 0.01). Feeding 35% WDGS in DRC and SFC-based finishing diets shifts fatty acids profiles toward increased saturated fatty acids and decreases extended shelf-life, but does not negatively impact intramuscular fat content and likely has little impact on beef taste and quality.