Effects of Extruded Corn or Grain Sorghum on Intake, Digestibility, Weight Gain, and Carcasses of Finishing Steers

Authors

R. J. Gaebe, University of Wyoming
D. W. Sanson, University of Wyoming
Ivan G. Rush, University of Nebraska-LincolnFollow
M. L. Riley, University of Wyoming
D. L. Hixon, University of WyomingFollow
S. I. Paisley, University of WyomingFollow

Date of this Version

1998

Comments

Published in Journal of Animal Science No. 76, pp. 2001-2007, 1998. Used by permission.

Abstract

We conducted two trials to evaluate the effects of extruding vs dry-rolling either corn or grain sorghum on intake, digestibility, and performance of finishing steers. In Trial 1, 92 crossbred steers (average BW 413 kg) were used in a 2 x 2 factorial design. Diets contained either dry-rolled corn (RC), extruded corn (EC), dry-rolled grain sorghum (RGS), or extruded grain sorghum (EGS). Diets were fed for 110 d and contained 78.6% of the respective grain, 9% alfalfa pellets, 8.2% molasses, and 4.2% protein-mineral supplement. Daily gain was highest (P < .049) for steers fed RC, and the ADG of steers fed RGS was higher than that of steers fed extruded diets; there was no difference in ADG between steers fed EC and those fed EGS. Steers fed dry-rolled diets consumed more DM (P = .001) than steers fed extruded diets. Feed efficiency was not affected (P = .18) by processing method, but steers fed corn utilized the diets more efficiently (P = .006) than steers fed grain sorghum. Except for carcass weight, carcass data were not affected by grain type (P > .20). Dressing percentage, quality grade, and longissimus muscle area were lower (P < .09) in steers that received extruded grain than in those that received dry-rolled grain. In Trial 2, five ruminally cannulated crossbred steers (average BW 518 kg) were used in a 4 x 4 + 1 Latin square design to evaluate the ruminal and total tract digestion characteristics of the diets used in Trial 1. Type of grain had no effect (P > .16) on intake, total tract digestibility, or ruminal pH. Extruding corn or grain sorghum decreased intake (P < .001) but increased (P < .074) DM and starch digestibility compared with dry rolling; steers fed extruded diets had lower (P < .032) ADF and NDF digestibilities. Ruminal in situ DM and starch disappearance were higher ( P < .03) and ruminal pH was lower (P < .052) in steers fed extruded grains than in those fed dry-rolled grains. Data from this study indicate that extruded corn and extruded grain sorghum are highly degradable feeds; however, decreased DM intake and lower ruminal pH levels resulted in lower performance.