| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Animal Science, Cornell University, Ithaca, NY 14853
2 Faculty of Veterinary Science, University of Sydney/Rumentek (Pty) Ltd., Parkside, SA, Australia
3 Bioproducts Inc., Fairlawn, OH 44333
Corresponding author: D. E. Bauman; E-mail: deb6{at}cornell.edu.
Abomasal infusion studies have shown that trans-10, cis-12 conjugated linoleic acid (CLA) decreases milk fat synthesis. However, supplements of CLA must avoid rumen biohydrogenation for this technology to be applied to ruminants. Rumen protection methods would reduce CLA metabolism in the rumen and increase its supply to the small intestine. Our objective was to compare the efficacy of 2 forms of rumen-protected CLA at inducing milk fat depression. Three mid to late lactation Holstein cows each fitted with a rumen fistula were used in a 3 x 3 Latin square design. Treatments were: 1) control, 2) calcium salts of CLA (Ca-CLA), and 3) formaldehyde-protected CLA (FP-CLA). Supplements were designed to provide 10 g/d of trans-10, cis-12 CLA and were administered intraruminally once per day to ensure exact delivery of amount. Both CLA treatments substantially reduced milk fat yield and content compared with control, with the reductions in milk fat yield averaging 34% for the Ca-CLA treatment and 44% for the FP-CLA treatment. In contrast, milk yield, milk protein yield, and dry matter intake were unaltered by CLA treatment. Efficiency of transfer of trans-10, cis-12 CLA from the supplement into milk fat was 3.2 and 7.0% for Ca-CLA and FP-CLA, respectively. These values are much lower than transfer efficiencies reported for abomasally infused CLA, suggesting that much of the trans-10, cis-12 CLA present in the 2 formulations was biohydrogenated in the rumen. Overall, the extent of the reduction in milk fat yield indicates that both protection formulations are acceptable methods for the formulation of CLA supplements to induce milk fat depression in lactating dairy cows.
Key Words: conjugated linoleic acid • milk fat • milk fat depression • rumen protection
Abbreviation key: Ca-CLA = calcium salts of conjugated linoleic acid, CLA = conjugated linoleic acid(s), FP-CLA = formaldehyde-protected conjugated linoleic acid, MFD = milk fat depression
This article has been cited by other articles:
|
|
 |
|
  E. Castaneda-Gutierrez, M. J. de Veth, A. L. Lock, D. A. Dwyer, K. D. Murphy, and D. E. Bauman Effect of Supplementation with Calcium Salts of Fish Oil on n-3 Fatty Acids in Milk Fat J Dairy Sci, September 1, 2007; 90(9): 4149 - 4156. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Castaneda-Gutierrez, B. C. Benefield, M. J. de Veth, N. R. Santos, R. O. Gilbert, W. R. Butler, and D. E. Bauman Evaluation of the Mechanism of Action of Conjugated Linoleic Acid Isomers on Reproduction in Dairy Cows J Dairy Sci, September 1, 2007; 90(9): 4253 - 4264. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. J. Odens, R. Burgos, M. Innocenti, M. J. VanBaale, and L. H. Baumgard Effects of Varying Doses of Supplemental Conjugated Linoleic Acid on Production and Energetic Variables During the Transition Period J Dairy Sci, January 1, 2007; 90(1): 293 - 305. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. de Veth, E. Castaneda-Gutierrez, D. A. Dwyer, A. M. Pfeiffer, D. E. Putnam, and D. E. Bauman Response to Conjugated Linoleic Acid in Dairy Cows Differing in Energy and Protein Status J Dairy Sci, December 1, 2006; 89(12): 4620 - 4631. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. M. Carroll, E. J. DePeters, and M. Rosenberg Efficacy of a Novel Whey Protein Gel Complex to Increase the Unsaturated Fatty Acid Composition of Bovine Milk Fat J Dairy Sci, February 1, 2006; 89(2): 640 - 650. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
