TY - JOUR
T1 - Trans-10 octadecenoic acid does not reduce milk fat synthesis in dairy cows
AU - Lock, Adam L.
AU - Tyburczy, Cynthia
AU - Dwyer, Debra A.
AU - Harvatine, Kevin J.
AU - Destaillats, Frédéric
AU - Mouloungui, Zéphirin
AU - Candy, Laure
AU - Bauman, Dale E.
PY - 2007/1
Y1 - 2007/1
N2 - Diet-induced milk fat depression (MFD) involves the interrelation between rumen fermentation and mammary synthesis of milk fat, and the reduction in milk fat coincides with a marked increase in the trans-10 18:1 content of milk fat. Our objective was to directly examine the effect of trans-10 18:1 on milk fat synthesis in dairy cows. Three mid-lactation cows were used in a 3 x 3 Latin square design; treatments were abomasal infusion of: 1) ethanol (control); 2) trans-10 18:1 (t10); and 3) trans-10, cis-12 conjugated linoleic acid (CLA; positive control). The t10 and CLA supplements (>90% purity) were infused for 4 d and provided 42.6 and 4.3 g/d of trans-10 18:1 and trans-10, cis-12 CLA, respectively. Milk yield, feed intake, milk protein, and milk lactose were unaffected by treatment. Compared with the control, the t10 treatment had no effect on milk fat synthesis, whereas the CLA treatment resulted in a 27 and 24% reduction in milk fat content and yield, respectively. The transfer efficiency of the abomasally infused trans-10 18:1 and trans-10, cis-12 CLA intomilk fat was 15 ± 1 and 23 ± 5% (means ± SD), respectively. Overall, trans-10 18:1 had no effect on milk fat synthesis when abomasally infused at ∼43 g/d, although it was taken up by the mammary glands and incorporated into milk fat. Therefore, our results offer no support for the concept that changes in rumen production of trans-10 18:1 within the physiological range play a role in the regulation of fatty acid synthesis during diet-induced MFD.
AB - Diet-induced milk fat depression (MFD) involves the interrelation between rumen fermentation and mammary synthesis of milk fat, and the reduction in milk fat coincides with a marked increase in the trans-10 18:1 content of milk fat. Our objective was to directly examine the effect of trans-10 18:1 on milk fat synthesis in dairy cows. Three mid-lactation cows were used in a 3 x 3 Latin square design; treatments were abomasal infusion of: 1) ethanol (control); 2) trans-10 18:1 (t10); and 3) trans-10, cis-12 conjugated linoleic acid (CLA; positive control). The t10 and CLA supplements (>90% purity) were infused for 4 d and provided 42.6 and 4.3 g/d of trans-10 18:1 and trans-10, cis-12 CLA, respectively. Milk yield, feed intake, milk protein, and milk lactose were unaffected by treatment. Compared with the control, the t10 treatment had no effect on milk fat synthesis, whereas the CLA treatment resulted in a 27 and 24% reduction in milk fat content and yield, respectively. The transfer efficiency of the abomasally infused trans-10 18:1 and trans-10, cis-12 CLA intomilk fat was 15 ± 1 and 23 ± 5% (means ± SD), respectively. Overall, trans-10 18:1 had no effect on milk fat synthesis when abomasally infused at ∼43 g/d, although it was taken up by the mammary glands and incorporated into milk fat. Therefore, our results offer no support for the concept that changes in rumen production of trans-10 18:1 within the physiological range play a role in the regulation of fatty acid synthesis during diet-induced MFD.
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U2 - 10.1093/jn/137.1.71
DO - 10.1093/jn/137.1.71
M3 - Article
C2 - 17182803
AN - SCOPUS:33845988000
SN - 0022-3166
VL - 137
SP - 71
EP - 76
JO - Journal of Nutrition
JF - Journal of Nutrition
IS - 1
ER -