|MAXWELL, CASEY - West Texas A & M University|
|BROWN, MIKE - West Texas A & M University|
|COUFAL, BILL - West Texas A & M University|
|WALLACE, J. - West Texas A & M University|
|SIMROTH-RODRIGUEZ, JORGE - West Texas A & M University|
|PRATT, SHAWNA - West Texas A & M University|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 5/7/2010
Publication Date: 7/12/2010
Citation: Maxwell, C.L., Brown, M.S., Cole, N.A., Coufal, B., Wallace, J.O., Simroth-Rodriguez, J., Pratt, S. 2010. Effects of roughage source and dried corn distiller's grains concentration on feedlot performance and carcass characteristics [abstract]. Journal of Animal Science Supplement. 88:E-Supplement 2, Paper 1003. p. 823.
Technical Abstract: Physical attributes of roughages used in finishing diets may impact the extent of ruminal digestion of dried distiller's grains (DDG) and growth performance. Crossbred steers (n=380) were adapted to a common finishing diet, blocked by BW, implanted with Revalor-S (120 mg of trenbolone acetate and 24 mg of estradiol), and assigned to treatments of roughage source (sorghum-sudan hay [SH] or sorghum-sudan silage [SS]) and DDG concentration (0 or 20% of diet DM). Cattle were housed in 40 soil-surfaced pens with at least 16.7 m**2 of pen space and 30.5 cm of bunk space/animal. Roughages were included on an equal NDF basis. All diets contained 3.4% non-protein N from urea (1.2% urea) and cottonseed meal was utilized as a protein source in 0% DDG diets. Cattle were fed twice/d for 108 d (initial BW = 410 +/- 13 kg). Steers fed 20% DDG ate 4.1% more DM than steers fed 0% DDG (10.42 vs. 10.85 kg, P = 0.007), but SS or SH did not influence DMI (P = 0.55). Overall shrunk ADG on a live basis was not altered by treatment (P > 0.57). Gain efficiency on a live basis was not altered by SS or SH (P = 0.77), but steers fed 0% DDG were 2.8% more efficient than steers fed 20% DDG (P = 0.008). There was a roughage source x DDG interaction for carcass-adjusted ADG and gain efficiency, dressing percentage, hot carcass weight, and LM area (P < 0.08). Adjusted ADG was increased 7% by 20% DDG with SS (P = 0.05), but not with SH (P = 0.39). Gain efficiency was reduced (P = 0.03) 4.8% by 20% DDG with SH, but was not altered (P = 0.71) with SS. Dressing percentage was reduced by 20% DDG with SH (63.0 vs. 62.4, P = 0.02) and increased by 20% DDG with SS (62.4 vs. 63.3, P < 0.001). Hot carcass weight was not altered by DDG with SH, but was increased 8 kg by 20% DDG with SS. The LM area was increased by 20% DDG with SS (P = 0.02), but not with SH (P = 0.29). Marbling score was higher when DDG was fed with SS or SH (380 vs. 390, P = 0.06). Results suggest that rate of gain on a carcass basis can be improved by feeding DDG with SS, but performance can be reduced when DDG is fed with SH.