Journal of Animal Science, Vol 77, Issue 7 1919-1929, Copyright © 1999 by American Society of Animal Science

JOURNAL ARTICLE

Effects of saturation and esterification of fat sources on site and extent of digestion in steers: digestion of fatty acids, triglycerides, and energy

J. P. Elliott, J. K. Drackley, A. D. Beaulieu, C. G. Aldrich and N. R. Merchen
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.

Five steers (mean BW 526 kg) fitted with ruminal, duodenal, and ileal cannulas were used in a 5 x 6 Youden square design with 14-d periods. Diets contained chopped alfalfa hay, corn silage, and concentrate (25:35:40, DM basis). Treatments were 1) control (no added fat); 2) tallow (T), iodine value (IV) = 51.5; 3) partially hydrogenated tallow (PHT), IV = 30.7; 4) hydrogenated tallow (HT), IV = 6.9; 5) blend (1: 1) of HT and hydrogenated free fatty acids (HTHFA), IV = 9.0; and 6) hydrogenated free fatty acids (HFA), IV = 11.2. Fats replaced cornstarch in the control diet to supply 5% added fatty acids. Intake was restricted to 90% of ad libitum; DMI was similar among diets (mean 9 kg/d). Total fatty acid intake averaged 170, 500, 506, 525, 489, and 491 g/d for treatments 1 to 6, respectively. Flows of total C16, total C18, and total fatty acids to the duodenum were increased by supplemental fat; flows of total C18 and total fatty acids were greater than their intake for all treatments. Flow of total fatty acids associated with ruminal bacteria accounted for 50 and 17% of the total duodenal fatty acid flow for the control and fat-supplemented diets, respectively. Digestibility of total fatty acids entering the small intestine (74, 71, 62, 39, 53, and 63% for treatments 1 to 6, respectively) was greater for the control diet than for fat-supplemented diets and decreased as either saturation (T < PHT < HT) or esterification (HFA < HTHFA < HT) increased. Digestibilities of fatty acids in the total tract followed similar patterns. Ruminal lipolysis of dietary triglycerides decreased linearly as the degree of saturation of fat sources increased. Small intestinal disappearance of triglycerides (89, 75, 51, 44, 64, and 73% of duodenal flow for treatments 1 to 6, respectively) decreased linearly as either saturation or esterification increased. Flows and digestion of gross energy followed patterns similar to those for fatty acids and triglycerides. Resistance to ruminal and small intestinal lipolysis is a major factor contributing to the poor digestibility of highly saturated triglycerides.

This article has been cited by other articles:

				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]

				H. J. LaBrune, C. D. Reinhardt, M. E. Dikeman, and J. S. Drouillard Effects of grain processing and dietary lipid source on performance, carcass characteristics, plasma fatty acids, and sensory properties of steaks from finishing cattle J Anim Sci, January 1, 2008; 86(1): 167 - 172. [Abstract] [Full Text] [PDF]

				B. Vlaeminck, V. Fievez, D. Demeyer, and R. J. Dewhurst Effect of forage:concentrate ratio on fatty acid composition of rumen bacteria isolated from ruminal and duodenal digesta. J Dairy Sci, July 1, 2006; 89(7): 2668 - 2678. [Abstract] [Full Text] [PDF]

				K. J. Harvatine and M. S. Allen Effects of Fatty Acid supplements on ruminal and total tract nutrient digestion in lactating dairy cows. J Dairy Sci, March 1, 2006; 89(3): 1092 - 1103. [Abstract] [Full Text] [PDF]

				R. L. Atkinson, E. J. Scholljegerdes, S. L. Lake, V. Nayigihugu, B. W. Hess, and D. C. Rule Site and extent of digestion, duodenal flow, and intestinal disappearance of total and esterified fatty acids in sheep fed a high-concentrate diet supplemented with high-linoleate safflower oil J Anim Sci, February 1, 2006; 84(2): 387 - 396. [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]

				W. P. Weiss and D. J. Wyatt Digestible Energy Values of Diets with Different Fat Supplements when Fed to Lactating Dairy Cows J Dairy Sci, May 1, 2004; 87(5): 1446 - 1454. [Abstract] [Full Text] [PDF]

				P. Bas, H. Archimede, A. Rouzeau, and D. Sauvant Fatty Acid Composition of Mixed-Rumen Bacteria: Effect of Concentration and Type of Forage J Dairy Sci, September 1, 2003; 86(9): 2940 - 2948. [Abstract] [Full Text] [PDF]