| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Animal and Avian Sciences, University of Maryland, College Park 20742
2 Department of Chemistry and Biochemistry, University of Maryland, College Park 20742
3 Nutrient Conservation and Metabolism Laboratory, Livestock and Poultry Sciences Institute, USDA, Agricultural Research Service, Beltsville, MD 20705
Fat supplementation of diets for dairy cows produces changes in nutrient supply and milk composition. The effect of abomasal infusion of either cis-C18:1 or trans-C18:1 fatty acid isomers on the digestibility of fatty acids and milk composition was determined in lactating dairy cows. Six multiparous midlactation Holstein cows were used and fed a control diet containing 50% forage and 50% concentrate. Treatments were (per day): no infusion, infusion of a 630-g fat mixture high in cis-C18:1 isomers, and infusion of a 623-g fat mixture high in trans-C18:1 isomers using two 3 x 3 Latin squares with 4-wk experimental periods. Fat infusion did not affect total dry matter intake and increased apparent digestibilities of total fatty acids. Apparent digestibilities of C18 fatty acids were directly related to the number of double bonds within isomers, and cis-C18:1 isomers were slightly more digestible than trans-C18:1 isomers. The lower yield of C12:0, C14:0, and C16:0 fatty acids in milk fat and higher milk citrate observed when cows were infused with trans-C18:1 suggests a depressed de novo milk fatty acid synthesis. Effects of trans infusion on milk fat were independent of ruminal fermentation, fatty acid apparent absorption, and fatty acid plasma concentrations. Lower milk protein yield in cows infused with fat may have been caused by a decrease in milk protein synthesis.
Key Words: cis-C18:1 fatty acids • trans-C18:1 fatty acids • milk fat depression • digestibility
Submitted on January 11, 1999
Accepted on May 8, 2000
This article has been cited by other articles:
|
|
 |
|
  K. J. Shingfield, A. Saebo, P.-C. Saebo, V. Toivonen, and J. M. Griinari Effect of abomasal infusions of a mixture of octadecenoic acids on milk fat synthesis in lactating cows J Dairy Sci, September 1, 2009; 92(9): 4317 - 4329. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Glasser, A. Ferlay, M. Doreau, P. Schmidely, D. Sauvant, and Y. Chilliard Long-Chain Fatty Acid Metabolism in Dairy Cows: A Meta-Analysis of Milk Fatty Acid Yield in Relation to Duodenal Flows and De Novo Synthesis J Dairy Sci, July 1, 2008; 91(7): 2771 - 2785. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. E. Mosley, B. Shafii{dagger}, P. J. Moate, and M. A. McGuire cis-9, trans-11 Conjugated Linoleic Acid Is Synthesized Directly from Vaccenic Acid in Lactating Dairy Cattle J. Nutr., March 1, 2006; 136(3): 570 - 575. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Gonthier, A. F. Mustafa, D. R. Ouellet, P. Y. Chouinard, R. Berthiaume, and H. V. Petit Feeding Micronized and Extruded Flaxseed to Dairy Cows: Effects on Blood Parameters and Milk Fatty Acid Composition J Dairy Sci, February 1, 2005; 88(2): 748 - 756. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. T. Selberg, A. C. Lowe, C. R. Staples, N. D. Luchini, and L. Badinga Production and Metabolic Responses of Periparturient Holstein Cows to Dietary Conjugated Linoleic Acid and trans-Octadecenoic Acids J Dairy Sci, January 1, 2004; 87(1): 158 - 168. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. V. Petit Digestion, Milk Production, Milk Composition, and Blood Composition of Dairy Cows Fed Formaldehyde Treated Flaxseed or Sunflower Seed J Dairy Sci, August 1, 2003; 86(8): 2637 - 2646. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
