Journal of Animal Science, Vol 72, Issue 8 1943-1953, Copyright © 1994 by American Society of Animal Science

JOURNAL ARTICLE

Dietary energy source and density: effects of roughage source, roughage equivalent, tallow level, and steer type on feedlot performance and carcass characteristics

S. J. Bartle, R. L. Preston and M. F. Miller
Texas Tech University, Lubbock 79409-2141.

The effects of roughage level (10, 20, or 30% roughage equivalent [RE]), roughage source (alfalfa vs cottonseed hulls), roughage regimen (constant RE vs 2% RE during the mid-finishing period), tallow level (1.2 vs 4.6%), and steer type (British crossbred [BRITX] vs Bos indicus crosses [BRX]) were evaluated in three experiments with a common allotment and several overlapping treatments. Steers (n = 432; initial weight = 326 +/- 26 kg) were divided into three BW blocks and allotted randomly to 72 pens and 24 treatments. Steers were fed steam-flaked, sorghum grain-based finishing diets for 124 to 166 d. Diets with 20% RE decreased gain efficiency and 30% RE diets decreased both gain (linear, P < .07) and efficiency (linear, P < .001) compared with 10% RE diets. Reducing roughage level during the mid-finishing period improved overall gain efficiency 2, 7, and 24% (P > .2, < .05, and < .001, respectively) for the 10, 20, and 30% RE diets, respectively. Steers fed cottonseed hulls consumed more feed (9.6 vs 8.8 kg/d, P < .001) but tended to gain less (1.53 vs 1.58 kg/d, P = .11) than steers fed alfalfa, were leaner, and had fewer carcasses grading Choice (62 vs 77%, P < .05). Feeding 4.6% tallow decreased DMI (P < .05) and improved gain efficiency (P < .05) compared with 1.2% tallow. The BRITX steers consumed more feed (6%, P < .001) but were somewhat less efficient (3.5%, P < .05) than BRX steers. Carcasses from BRITX steers tended to be fatter than carcasses from BRX steers and more of them graded Choice (62 vs 37%, P < .01). Commercial BRX steers did not perform as well as BRITX steers on higher-energy-density diets (4.6% tallow or variable roughage regimen). Knowledge of the genetic background of feeder cattle can be important in the selection of dietary energy density and marketing expectations.

This article has been cited by other articles:

				H. M. Arelovich, C. S. Abney, J. A. Vizcarra, and M. L. Galyean Effects of Dietary Neutral Detergent Fiber on Intakes of Dry Matter and Net Energy by Dairy and Beef Cattle: Analysis of Published Data Professional Animal Scientist, October 1, 2008; 24(5): 375 - 383. [Abstract] [PDF]

				F. Loya-Olguin, L. Avendano-Reyes, A. M. Encinias, D. A. Walker, N. A. Elam, and S. A. Soto-Navarro Influence of slice baling on feeding value of alfalfa hay in receiving and finishing diets for feedlot cattle J Anim Sci, October 1, 2008; 86(10): 2749 - 2755. [Abstract] [Full Text] [PDF]

				J. J. Cranston, J. D. Rivera, M. L. Galyean, M. M. Brashears, J. C. Brooks, C. E. Markham, L. J. McBeth, and C. R. Krehbiel Effects of feeding whole cottonseed and cottonseed products on performance and carcass characteristics of finishing beef cattle J Anim Sci, August 1, 2006; 84(8): 2186 - 2199. [Abstract] [Full Text] [PDF]

				T. D. Maddock, M. L. Bauer, K. B. Koch, V. L. Anderson, R. J. Maddock, G. Barcelo-Coblijn, E. J. Murphy, and G. P. Lardy Effect of processing flax in beef feedlot diets on performance, carcass characteristics, and trained sensory panel ratings J Anim Sci, June 1, 2006; 84(6): 1544 - 1551. [Abstract] [Full Text] [PDF]

				C. R. Krehbiel, J. J. Cranston, and M. P. McCurdy An upper limit for caloric density of finishing diets J Anim Sci, April 1, 2006; 84(13_suppl): E34 - E. [Abstract] [Full Text] [PDF]

				M. L. Nelson, D. J. Marks, J. R. Busboom, J. D. Cronrath, and L. Falen Effects of supplemental fat on growth performance and quality of beef from steers fed barley-potato product finishing diets: I. Feedlot performance, carcass traits, appearance, water binding, retail storage, and palatability attributes J Anim Sci, December 1, 2004; 82(12): 3600 - 3610. [Abstract] [Full Text] [PDF]

				D. J. Gibb, F. N. Owens, P. S. Mir, Z. Mir, M. Ivan, and T. A. McAllister Value of sunflower seed in finishing diets of feedlot cattle J Anim Sci, September 1, 2004; 82(9): 2679 - 2692. [Abstract] [Full Text] [PDF]

				M. L. Galyean and P. J. Defoor Effects of roughage source and level on intake by feedlot cattle J Anim Sci, February 1, 2003; 81(14_suppl_2): E8 - 16. [Abstract] [Full Text] [PDF]