Short communication: milk fat response to low doses of tran-10, cis-12 conjugated linoleic acid (CLA).
Trans-10, cis-12 conjugated linoleic acid (CLA) is a potent inhibitor of milk fat synthesis. We examined the effect of low doses of trans-10, cis-12 CLA using Holstein cows in a 4 x 4 Latin square design. Milk yield and milk protein were unaffected, but abomasal infusion of 1.25, 2.5, and 5.0 g/d of trans-10, cis-12 CLA reduced milk fat yield by 7, 16, and 29%, respectively. When combined with previous data, the reduction in milk fat yield was curvilinear, relating to both quantity infused and milk fat content of trans-10, cis-12 CLA (R2 = 0.99 and 0.96, respectively). Further, changes in milk fatty acid composition indicated the mechanism involved inhibition of de novo fatty acid synthesis and the utilization of circulating fatty acids.
Department of Animal Science, Cornell University, Ithaca, NY 14853, USA.
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Peterson
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Baumgard
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Bauman
D000018:Abomasum; D000818:Animals; D002417:Cattle / Q000378:metabolism / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage* / Q000378:metabolism; D005260:Female; D007774:Lactation; D019787:Linoleic Acid / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D008055:Lipids / Q000032:analysis / Q000096:biosynthesis*; D008892:Milk / Q000737:chemistry* / Q000378:metabolism; D011897:Random Allocation; D013237:Stereoisomerism
D005231:Fatty Acids, Unsaturated; D008055:Lipids; D019787:Linoleic Acid