Quality and Composition of Beef from Cattle Fed Combinations of Steam-flaked Corn, Dry-rolled Corn, and Distiller's Grains with Solubles

Transcription

1 Quality and Composition of Beef from Cattle Fed Combinations of Steam-flaked Corn, Dry-rolled Corn, and Distiller's Grains with Solubles J.S. Drouillard Kansas State University Manhattan, Kansas 66506

2 Introduction Distiller s grains (DDGS) are becoming widely used in cattle finishing systems throughout the U.S. Little research has been done to evaluate mixtures of grains and DDGS, and their effects on meat quality and sensory characteristics

3 Objectives To evaluate the effects of feeding combinations of flaked corn, dry-rolled corn, and DDGS on meat quality and sensory attributes, including: Carcass quality and yield grades Moisture purge loss during wet aging Weight loss during cooking Vitamin E concentration TBARS Retail color display life Sensory attributes (trained sensory panel)

4 Materials and Methods Crossbred heifers (n=700, 665 lb initial weight) Individually weighed Blocked into light and heavy weight groups Within block, randomly allocated to treatments 25 heifers per pen 7 pens per treatment Fed free choice Fed for 137 to 157 d

5 Experimental Design 2 x 2 Factorial Level of dry-rolled corn (DRC) 0 or 25% (DM basis) Level of dried distiller s grains with solubles (DDGS) 0 or 25% (DM basis) Statistical Analysis MIXED Procedure of SAS (ver. 9.1) Fixed effects of DRC, DDGS, and block Interaction between DRC and DDGS

6 Materials and Methods Crossbred heifers (n=700, kg initial BW) Individually weighed Blocked into light and heavy weight groups Within block, randomly allocated to treatments 25 heifers per pen 7 pens per treatment Fed once daily ad libitum Fed for 137 to 157 d

7 Experimental Design 2 x 2 Factorial Level of dry-rolled corn (DRC) 0 or 25% (DM basis) Level of dried distiller s grains with solubles (DDGS) 0 or 25% (DM basis) Statistical Analysis MIXED Procedure of SAS (ver. 9.1) Fixed effects of DRC, DDGS, and block Interaction between DRC and DDGS

8 Materials and Methods Whole rib sections Collected from 24 pens 6 pens per treatment 4 heifers randomly selected per pen 94 rib sections collected

9 Purge loss 6 th, 7 th, and 8 th rib sections were weighed, then wet aged for 2 wk Cooking loss Steaks used for sensory were weighed before and after cooking Lipid Oxidation (TBARS) TBARS measured following a 7-day simulated retail display period Vitamin E Concentrations Concentration of alpha-tocopherol

10 Retail display life 1-inch steaks were from the 6 th rib section Readings were taken by Miniscan XE spectrophotometer Readings taken daily at three different locations and averaged Steaks were rotated twice daily Sensory traits Five-member trained panel 15-point scale

11 Diets, DM basis 0% DRC 25% DRC Ingredient, % DM 0% DDGS 25% DDGS 0% DDGS 25% DDGS Steam-flaked corn DDGS Dry-rolled corn Alfalfa hay Corn steep liquor Urea Supplement 1, Formulated to provide 300 mg Rumensin, 90 mg Tylan, 0.5 mg MGA, 1000 IU/lb vitamin A, 10 IU/lb vitamin E, 0.30% salt, 0.70% calcium, 0.70% potassium, 60 ppm Zn, 60 ppm Mn, 10 ppm Cu, 0.6 ppm I, 0.25 ppm Se, and 0.1 ppm Co. 2 Optaflexx was fed for the last 42 days at 200 mg/day.

12 Feedlot Performance 0% DRC 25% DRC Item 0% DDGS 25% DDGS 0% DDGS 25% DDGS SEM Head count Final live body weight, lb a Feed intake, lb/day ADG, lb b F:G b a Weight after 4% pencil shrink.

13 Carcass Characteristics 0% DRC 25% DRC Item 0%DDGS 25%DDGS 0% DDGS 25% DDGS SEM Dressed yield, % a Hot carcass weight, lb Marbling score b Slight 92 Slight 93 Slight 99 Slight Liver abscess, % a DRC effect (P < 0.05)

14 USDA Quality Grades 0% DRC 25% DRC Item 0% DDGS 25% DDGS 0% DDGS 25% DDGS SEM Prime, % Upper 2/3 rds Choice, % Low Choice, % Select, % Standard, %

15 USDA Yield Grades 0% DRC 25% DRC Item 0% DDGS 25% DDGS 0% DDGS 25% DDGS SEM Yield grade 1, % a Yield grade 2, % Yield grade 3, % Yield grade 4, % Yield grade 5, % a DRC*DDGS interaction (P < 0.05)

16 Carcass Value 0% DRC 25% DRC Item 0% DDGS 25% DDGS 0% DDGS 25% DDGS SEM Value per CWT, $ Total carcass value, $

17 Purge Loss During 2-week Wet Aging SEM =

18 Weight Loss During Cooking DRC effect P < 0.05 SEM = Percent of initial weight

19 Vitamin E Concentrations DDG effect P < 0.05 SEM = 0.22 alpha-tocopherol, mg/kg

20 TBARS (Lipid Oxidation) SEM = Malonaldehyde, mg/g

21 L* During 7-d Retail Display SEM = Spectrophotometer reading

22 a* During 7-d Retail Display SEM = Spectrophotometer reading

23 b* During 7-d Retail Display SEM = Spectrophotometer reading

24 Saturation Index During 7-d Retail Display SEM = 0.77

25 Hue Angle During 7-d Retail Display SEM = 0.60

26 Sensory Attributes Trained Panel a 0% DRC 25% DRC Item 0% DDGS 25% DDGS 0% DDGS 25% DDGS SEM Initial tenderness Juiciness Chewiness Mealy texture Fiber awareness Residual connective tissue a 15-point scale, where 15 represents the highest degree of the attribute in question

27 Flavor Attributes Trained Panel a 0% DRC 25% DRC Item 0% DDGS 25% DDGS 0% DDGS 25% DDGS SEM Beef flavor ID b Bloody/serumy Metallic flavor Rancid flavor a 15-point scale, where 15 represents the highest degree of the attribute in question b DRC*DDGS interaction (P < 0.05)

28 Summary No significant differences in ADG, DMI, F:G No significant differences in carcass weight, quality or yield grades, marbling score, liver abscess incidence

29 Conclusion DDGS can substitute for SFC with no detrimental effects on performance, carcass quality grade, or yield grade DRC can substitute for portions of SFC, decreasing grain processing costs with no negative consequences for performance or carcass value

30 Conclusion Feeding DDGS decreased vitamin E concentrations of meat, however did not change lipid oxidation Feeding steam-flaked corn diets with or without DRC and DDGS resulted in beef with comparable meat quality and sensory attributes