Journal of Animal Science, Vol 76, Issue 1 242-248, Copyright © 1998 by American Society of Animal Science

JOURNAL ARTICLE

Effect of degradable intake protein level on finishing cattle performance and ruminal metabolism

D. H. Shain, R. A. Stock, T. J. Klopfenstein and D. W. Herold
University of Nebraska, Lincoln 68583-0908, USA.

Two finishing trials and a metabolism trial were conducted to evaluate level of supplemental degradable intake (crude) protein (DIP) in finishing diets on cattle performance, carcass characteristics, and ruminal metabolism. Finishing trials were conducted in two consecutive years using 128 crossbred yearling steers (BW = 343+/-5 kg, Trial 1) and 176 crossbred yearling steers (BW = 375+/-4 kg, Trial 2) in a randomized complete block design. Steers were fed dry-rolled corn diets containing urea at 0, .88, 1.34, or 1.96% (DM basis). No differences in DMI, daily gain, or feed efficiency were noted among steers receiving diets containing supplemental urea. However, steers fed diets supplemented with urea were 5.4% more efficient (P < .01) and gained 6.6% faster (P < .01) than steers receiving no supplemental urea. Metabolizable protein (MP) content of all diets exceeded the steers' requirements. However, diets containing no urea were deficient in DIP. In the metabolism trial, four ruminally fistulated steers (BW = 380+/-22 kg) were used in a 4 x 4 Latin square design and fed (ad libitum) diets similar to those used in the finishing trials. Nitrogen intake and ruminal ammonia N concentration increased linearly (P < .05) with increasing level of urea supplementation. Diets containing no supplemental urea were calculated to be deficient in DIP, resulting in reduced bacterial synthesis. Results indicate that dry-rolled corn finishing diets containing no supplemental N are deficient in ruminally degradable N. Supplementing these diets with an inexpensive source of ruminally degradable N improved animal performance. However, supplementation with urea above .88% was not beneficial.

This article has been cited by other articles:

				N. A. Cole, P. J. Defoor, M. L. Galyean, G. C. Duff, and J. F. Gleghorn Effects of phase-feeding of crude protein on performance, carcass characteristics, serum urea nitrogen concentrations, and manure nitrogen of finishing beef steers J Anim Sci, December 1, 2006; 84(12): 3421 - 3432. [Abstract] [Full Text] [PDF]

				J. T. Vasconcelos, L. W. Greene, N. A. Cole, M. S. Brown, F. T. McCollum III, and L. O. Tedeschi Effects of phase feeding of protein on performance, blood urea nitrogen concentration, manure nitrogen:phosphorus ratio, and carcass characteristics of feedlot cattle J Anim Sci, November 1, 2006; 84(11): 3032 - 3038. [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]

				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]

				J. F. Gleghorn, N. A. Elam, M. L. Galyean, G. C. Duff, N. A. Cole, and J. D. Rivera Effects of crude protein concentration and degradability on performance, carcass characteristics, and serum urea nitrogen concentrations in finishing beef steers J Anim Sci, September 1, 2004; 82(9): 2705 - 2717. [Abstract] [Full Text] [PDF]

				J. J. Reed, G. P. Lardy, M. L. Bauer, T. C. Gilbery, and J. S. Caton Effect of field pea level on intake, digestion, microbial efficiency, ruminal fermentation, and in situ disappearance in beef steers fed growing diets J Anim Sci, July 1, 2004; 82(7): 2123 - 2130. [Abstract] [Full Text] [PDF]

				K. C. Swanson, H. C. Freetly, and C. L. Ferrell Nitrogen balance in lambs fed a high-concentrate diet and infused with differing proportions of casein in the rumen and abomasum J Anim Sci, February 1, 2004; 82(2): 495 - 501. [Abstract] [Full Text] [PDF]