Regulation and Nutritional Manipulation of Milk Fat
CertaindietsinduceMFDinlactatingdairycowsandseveraltheories havebeenproposedasthebasis.Oneoftheseistheglucogenic-insulin theory, but recent investigations offer no support for this theory as the cause of MFD. Another theory is that intermediates formed in rumen biohydrogenation of unsaturated fatty acids inhibit fat synthesis at the mammary gland. Recent studies suggest that pathways of rumen biohydrogenation are altered under certain dietary conditions and this results in a shift in the CLA and transC18:1 isomers that are produced. Specifically, diet-induced MFD corresponds to increases in milk fat content of trans-10, cis-12CLA and trans-10 C18:1, and the former has been shown to be a potent inhibitor of milk fat synthesis.
KeywordsConjugate Linoleic Acid Trans Fatty Acid Conjugate Linoleic Acid Isomer Milk Fatty Acid Insulin Clamp
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