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ARS Home » Plains Area » Mandan, North Dakota » Northern Great Plains Research Laboratory » Research » Publications at this Location » Publication #190952
Title: SITE AND EXENT 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

Author
item ATKINSON, REBECCA - UNIVERSITY OF WYOMING
item Scholljegerdes, Eric
item LAKE, SCOTT - UNIVERSITY OF WYOMING
item NAYIGIHUGU, VENERAND - UNIVERSITY OF WYOMING
item HESS, BRETT - UNIVERSITY OF WYOMING
item RULE, DANIEL - UNIVERSITY OF WYOMING

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/3/2005
Publication Date: 2/1/2006
Citation: Atkinson, R.L., Scholljegerdes, E.J., Lake, S.L., Nayigihugu, V., Hess, B.W., Rule, D.C. 2006. Site and exent 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. 84:387-396.

Interpretive Summary: In order to increase unsaturated fatty acids to the tissues of ruminant animals, ruminal saturation of dietary fatty acids must be circumvented. One way to do this is by increasing the amount of esterified fatty acids reaching the small intestine. Therefore, our objective was to determine duodenal and ileal flows of total and esterified fatty acids and to determine ruminal fermentation characteristics and site and extent of nutrient digestion in sheep fed an 80% concentrate diet supplemented with high-linoleate (77%) safflower oil at 0, 3, 6, and 9% of dry matter intake. Increasing levels of dietary safflower oil increased the duodenal flow of linoleic acid along with other unsaturated fatty acids, indicating that the extent of ruminal saturation of unsaturated fatty acids was decreased. Intestinal supply of linoleic acid associated with total fatty acids was similar to intestinal flow of linoleic acid associated with esterified fatty acids. The levels of high-linoleate safflower oil fed, apparent disappearance from the intestine, and thus apparent absorption, of fatty acids ranged from 80 to 100%, indicating that intestinal lipolysis did not limit overall digestion of the fatty acids fed to the sheep. Producing ruminant meat and dairy products that are enriched with unsaturated fatty acids, such as various n-3, n-6, and conjugated linoleic acid, is desired. By feeding large dietary proportions of high-linoleate vegetable oils in high-concentrate diets, greater levels of linoleic acid and other polyunsaturated fatty acids will be available for incorporation into ruminant-derived food products.

Technical Abstract: Our objective was to determine duodenal and ileal flows of total and esterified fatty acids and to determine ruminal fermentation characteristics and site and extent of nutrient digestion in sheep fed an 80% concentrate diet supplemented with high-linoleate (77%) safflower oil at 0, 3, 6, and 9% of DM. Oil was infused intraruminally along with an isonitrogenous basal diet (fed at 2% of BW) that contained bromegrass hay, cracked corn, corn gluten meal, urea, and limestone. Four crossbred wethers (BW = 44.3 +/-'15.7 kg) fitted with ruminal, duodenal, and ileal cannulas were used in a 4 ''4 Latin square experiment, in which 14 d of dietary adaptation were followed by 4 d of duodenal, ileal, and ruminal sampling. Fatty acid intake increased (linear, P = 0.004 to 0.001) with increased dietary safflower oil. Digestibilities of OM, NDF, and N were not affected (P = 0.09 to 0.65) by increased dietary safflower oil. For total fatty acids (free plus esterified) and esterified fatty acids, duodenal flow of most fatty acids, including 18:2c-9,c-12, increased (P = 0.006 to 0.05) with increased dietary oil. Within each treatment, duodenal flow of total and esterified 18:2c-9,c-12 was similar (P = 0.32), indicating that duodenal flow of this fatty acid occurred because most of it remained esterified. Duodenal flow of esterified 18:1t-11 increased (P = 0.08) with increased dietary safflower oil, indicating that reesterification of ruminal fatty acids occurred. Apparent small intestinal disappearance of most fatty acids was not affected (P = 0.19 to 0.98) by increased dietary safflower oil, but increased (P = 0.05) for 18:2c-9,c-12, which ranged from 87.0 to 97.4%, and for 18:2c- 9,t-11 (P = 0.03), which ranged from 37.9% with no added oil to 99.2% with supplemental oil. For esterified fatty acids, apparent small intestinal disappearance was from 80% for 18:3c-9,c-12,c-15 at the greatest level of dietary oil up to 100% for 18:1t-11 and 18:1c-12 with 0% oil. We concluded that duodenal flow of 18:2c-9,c-12 was predominately associated with the esterified fraction, suggesting that the extent of ruminal lipolysis was decreased with increased dietary high-linoleate safflower oil. Furthermore, biohydrogenation intermediates observed in the esterified fatty acids indicated that some reesterification occurred, and the high level of apparent absorption of esterified fatty acids indicated that intestinal lipolysis did not limit overall digestion of the fatty acids fed to the sheep.