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HERO ID
2951055
Reference Type
Journal Article
Title
Comparison of calcium salts and formaldehyde-protected conjugated linoleic acid in inducing milk fat depression
Author(s)
de Veth, MJ; Gulati, SK; Luchini, ND; Bauman, DE
Year
2005
Is Peer Reviewed?
Yes
Journal
Journal of Dairy Science
ISSN:
0022-0302
EISSN:
1525-3198
Volume
88
Issue
5
Page Numbers
1685-1693
Language
English
PMID
15829659
DOI
10.3168/jds.S0022-0302(05)72840-X
Web of Science Id
WOS:000228358800009
Abstract
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.
Keywords
conjugated linoleic acid; milk fat; milk fat depression; rumen protection
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