Synthesis and Biohydrogenation of Fatty Acids by Ruminal Microorganisms In Vitro

¹ Department of Dairy Science, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster 44691

Ruminal degradation, synthesis, and biohydrogenation of fatty acids were examined in vitro. Diets were incubated with ruminal contents, and changes of fatty acids were measured. Two fat supplements, a calcium soap and an animal-vegetable blend, were included in diets at various levels. Addition to diets of acetate and isoacids (collective term for certain short-chain acids) also were tested for effects on fatty acid synthesis. Overall, 6.6 mg of fatty acids/g of fat-free diet were synthesized during 24-h incubation regardless of supplementations. Fatty acids synthesized in greatest amounts were odd-numbered or branched chains, whereas chains of 16 and 18 carbons changed little, and chains shorter than 14 carbons decreased. Degradation of [1-¹⁴C]palmitic acid was negligible, as determined by recovery of the label in CO₂ (.03%) and acetate (1.09%) after 4-h incubation with rumen contents. Biohydrogenation of fatty acids averaged 47% in diets containing calcium soap and 71% with animal-vegetable blend. Synthesis and biohydrogenation were similar to those measured previously in vivo, showing that in vitro measurements reliably predicted metabolism of fatty acids in vivo.

Key Words: fatty acid synthesis • biohydrogenation • ruminal microorganisms

Submitted on January 22, 1991
Accepted on April 5, 1991

This article has been cited by other articles:

				E. Scholljegerdes and S. Kronberg Influence of level of supplemental whole flaxseed on forage intake and site and extent of digestion in beef heifers consuming native grass hay J Anim Sci, September 1, 2008; 86(9): 2310 - 2320. [Abstract] [Full Text] [PDF]

				Q. Sun, J. Ma, H. Campos, and F. B Hu Plasma and erythrocyte biomarkers of dairy fat intake and risk of ischemic heart disease Am. J. Clinical Nutrition, October 1, 2007; 86(4): 929 - 937. [Abstract] [Full Text] [PDF]

				M. M. Or-Rashid, N. E. Odongo, and B. W. McBride Fatty acid composition of ruminal bacteria and protozoa, with emphasis on conjugated linoleic acid, vaccenic acid, and odd-chain and branched-chain fatty acids J Anim Sci, May 1, 2007; 85(5): 1228 - 1234. [Abstract] [Full Text] [PDF]

				T. C. Jenkins, A. A. AbuGhazaleh, S. Freeman, and E. J. Thies The Production of 10-Hydroxystearic and 10-Ketostearic Acids Is an Alternative Route of Oleic Acid Transformation by the Ruminal Microbiota in Cattle J. Nutr., April 1, 2006; 136(4): 926 - 931. [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]

				K. J. Harvatine and M. S. Allen Fat Supplements Affect Fractional Rates of Ruminal Fatty Acid Biohydrogenation and Passage in Dairy Cows J. Nutr., March 1, 2006; 136(3): 677 - 685. [Abstract] [Full Text] [PDF]

				C. Reveneau, C. V. D. M. Ribeiro, M. L. Eastridge, N. R. St-Pierre, and J. L. Firkins Processing Whole Cottonseed Moderates Fatty Acid Metabolism and Improves Performance by Dairy Cows J Dairy Sci, December 1, 2005; 88(12): 4342 - 4355. [Abstract] [Full Text] [PDF]

				L. S. Piperova, U. Moallem, B. B. Teter, J. Sampugna, M. P. Yurawecz, K. M. Morehouse, D. Luchini, and R. A. Erdman Changes in Milk Fat in Response to Dietary Supplementation with Calcium Salts of Trans-18:1 or Conjugated Linoleic Fatty Acids in Lactating Dairy Cows J Dairy Sci, November 1, 2004; 87(11): 3836 - 3844. [Abstract] [Full Text] [PDF]

				J. J. Loor, W. H. Hoover, T. K. Miller-Webster, J. H. Herbein, and C. E. Polan Biohydrogenation of unsaturated fatty acids in continuous culture fermenters during digestion of orchardgrass or red clover with three levels of ground corn supplementation J Anim Sci, June 1, 2003; 81(6): 1611 - 1627. [Abstract] [Full Text] [PDF]

				F. Enjalbert, P. Eynard, M. C. Nicot, A. Troegeler-Meynadier, C. Bayourthe, and R. Moncoulon In Vitro Versus in Situ Ruminal Biohydrogenation of Unsaturated Fatty Acids from a Raw or Extruded Mixture of Ground Canola Seed/Canola Meal J Dairy Sci, January 1, 2003; 86(1): 351 - 359. [Abstract] [Full Text] [PDF]

				J. G. Giesy, M. A. McGuire, B. Shafii, and T. W. Hanson Effect of Dose of Calcium Salts of Conjugated Linoleic Acid (CLA) on Percentage and Fatty Acid Content of Milk Fat in Midlactation Holstein Cows J Dairy Sci, August 1, 2002; 85(8): 2023 - 2029. [Abstract] [Full Text] [PDF]

				A. Wolk, M. Furuheim, and B. Vessby Fatty Acid Composition of Adipose Tissue and Serum Lipids Are Valid Biological Markers Of Dairy Fat Intake in Men J. Nutr., March 1, 2001; 131(3): 828 - 833. [Abstract] [Full Text]

				A. E. Smedman, I.-B. Gustafsson, L. G. Berglund, and B. O. Vessby Pentadecanoic acid in serum as a marker for intake of milk fat: relations between intake of milk fat and metabolic risk factors Am. J. Clinical Nutrition, January 1, 1999; 69(1): 22 - 29. [Abstract] [Full Text] [PDF]