Journal of Animal Science, Vol 78, Issue 7 1738-1746, Copyright © 2000 by American Society of Animal Science

JOURNAL ARTICLE

Influence of ruminal biohydrogenation on the feeding value of fat in finishing diets for feedlot cattle

R. A. Zinn, S. K. Gulati, A. Plascencia and J. Salinas
Desert Research and Extension Center, University of California, El Centro 92243, USA. razinn@ucdavis.edu

Four Holstein steers (212 kg) with cannulas in the rumen and proximal duodenum were used in a 4 x 4 Latin square experiment to study the influence of degree of ruminal biohydrogenation (BH) on the feeding value of supplemental fat. Treatments consisted of an 88% concentrate finishing diet supplemented with 1) 2% yellow grease (control); 2) 4% formaldehyde-protected fat (Rumentek), 2% yellow grease (LBH); 3) 2% Rumentek, 4% yellow grease (MBH); or 4) 6% yellow grease (HBH). Ruminal BH of HBH, MBH, and LBH diets was 74, 68, and 54%, respectively. High-fat supplementation decreased (7%, P < .05) intestinal digestibility of 18:0 but increased intestinal digestibility of 18:1 (3%, P < .10), 18:2 (14%, P < .01), and 18:3 (23%, P < .05). Increases in intestinal digestibility of 18:0 (quadratic effect, P < .05), 18:1 (linear effect, P < .01), 18:2 (linear effect, P < .01), 18:3 (linear effect, P < .05), and total fatty acids (linear effect, P < .05) were inversely related to BH. For every 1% increase in the proportion of 18:1 fat entering the small intestine, the digestibility of 18:0 increased 1%. High-fat supplementation depressed ruminal digestion of OM (11%, P < .05), NDF (16%, P < .05), starch (6%, P < .05), and feed N (12%, P < .01). Formaldehyde-protein protection of fat diminished its depressing effects on ruminal digestion of NDF (quadratic effect, P < .10) and enhanced ruminal escape of feed N (linear effect, P < .10). Postruminal digestion of OM was greater (4.6%, P < .10) for high-fat diets. High-fat diets decreased (P < .05) total tract digestion of OM (1.9%), NDF (7.4%), and starch (.5%). Postruminal and total tract digestibility of OM, NDF, N, and starch was not affected (P > .10) by BH. In a 125-d finishing trial, 100 yearling steers (362 kg) were used to evaluate treatment effects on growth performance. High-fat diets did not affect (P > .10) ADG but increased (P < .10) feed efficiency (9%, P < .10), dietary NEm (7.6%, P < .05), and dressing percentage (9%, P < .05). The magnitude of the increase in dressing percentage was inversely related (linear effect, P < .10) to BH. We conclude that decreasing ruminal BH will increase postruminal digestibility of fat, and hence the NE value of dietary fat. The synergistic effect of increasing the proportion of 18:1 on intestinal digestion of fat enables higher levels of fat supplementation. Protecting fat from BH minimizes the detrimental effects of supplemental fat on fiber digestion.

This article has been cited by other articles:

				T. J. Klopfenstein, G. E. Erickson, and V. R. Bremer BOARD-INVITED REVIEW: Use of distillers by-products in the beef cattle feeding industry J Anim Sci, May 1, 2008; 86(5): 1223 - 1231. [Abstract] [Full Text] [PDF]

				B. W. Hess, G. E. Moss, and D. C. Rule A decade of developments in the area of fat supplementation research with beef cattle and sheep J Anim Sci, April 1, 2008; 86(14_suppl): E188 - E204. [Abstract] [Full Text] [PDF]

				S. P. Montgomery, J. S. Drouillard, T. G. Nagaraja, E. C. Titgemeyer, and J. J. Sindt Effects of supplemental fat source on nutrient digestion and ruminal fermentation in steers J Anim Sci, March 1, 2008; 86(3): 640 - 650. [Abstract] [Full Text] [PDF]

				S. Hutchison, E. B. Kegley, J. K. Apple, T. J. Wistuba, M. E. Dikeman, and D. C. Rule Effects of adding poultry fat in the finishing diet of steers on performance, carcass characteristics, sensory traits, and fatty acid profiles J Anim Sci, September 1, 2006; 84(9): 2426 - 2435. [Abstract] [Full Text] [PDF]

				O. Kucuk, B. W. Hess, and D. C. Rule Soybean oil supplementation of a high-concentrate diet does not affect site and extent of organic matter, starch, neutral detergent fiber, or nitrogen digestion, but influences both ruminal metabolism and intestinal flow of fatty acids in limit-fed lambs J Anim Sci, October 1, 2004; 82(10): 2985 - 2994. [Abstract] [Full Text] [PDF]

				M. H. Gillis, S. K. Duckett, and J. R. Sackmann Effects of supplemental rumen-protected conjugated linoleic acid or corn oil on fatty acid composition of adipose tissues in beef cattle J Anim Sci, May 1, 2004; 82(5): 1419 - 1427. [Abstract] [Full Text] [PDF]

				J. R. Sackmann, S. K. Duckett, M. H. Gillis, C. E. Realini, A. H. Parks, and R. B. Eggelston Effects of forage and sunflower oil levels on ruminal biohydrogenation of fatty acids and conjugated linoleic acid formation in beef steers fed finishing diets J Anim Sci, December 1, 2003; 81(12): 3174 - 3181. [Abstract] [Full Text] [PDF]

				A. Plascencia, G. D. Mendoza, C. Vasquez, and R. A. Zinn Relationship between body weight and level of fat supplementation on fatty acid digestion in feedlot cattle J Anim Sci, November 1, 2003; 81(11): 2653 - 2659. [Abstract] [Full Text] [PDF]

				S. K. Duckett, J. G. Andrae, and F. N. Owens Effect of high-oil corn or added corn oil on ruminal biohydrogenation of fatty acids and conjugated linoleic acid formation in beef steers fed finishing diets J Anim Sci, December 1, 2002; 80(12): 3353 - 3360. [Abstract] [Full Text] [PDF]