אסיף מאגר המחקר החקלאי

Changes in milk fat in response to dietary supplementation with calcium salts of trans-18:1 or conjugated linoleic fatty acids in lactating dairy cows

Year:

2004

Source of publication :

Authors :

Volume :

87

Co-Authors:

Piperova, L.S., Animal and Avian Sciences Department, University of Maryland, College Park, MD 20742, United States
Moallem, U., Animal and Avian Sciences Department, University of Maryland, College Park, MD 20742, United States
Teter, B.B., Dept. of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, United States
Sampugna, J., Dept. of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, United States
Yurawecz, M.P., US Food and Drug Administration, Ctr. for Food Safety and Appl. Nutr., College Park, MD 20742, United States
Morehouse, K.M., US Food and Drug Administration, Ctr. for Food Safety and Appl. Nutr., College Park, MD 20742, United States
Luchini, D., Bioproducts Inc., Fairlawn, OH 44333, United States
Erdman, R.A., Animal and Avian Sciences Department, University of Maryland, College Park, MD 20742, United States

Facilitators :

Link :

Abstract:

Milk fat was investigated in lactating dairy cows fed diets supplemented with Ca salts of trans fatty acids (Ca-tFA) or Ca salts of conjugated linoleic acids (Ca-CLA). Forty-five Holstein cows (115 days in milk) were fed a control diet (51% forage; dry matter basis) supplemented with 400 g of EnerG II (Ca salts of palm oil fatty acids) for 2 wk; subsequently, 5 groups of 9 cows each were assigned for 4 wk to the control diet or diets containing 100 g of Ca-CLA or 100, 200, or 400 g of Ca-tFA in a randomized block design. Treatments had no effect on dry matter intake, milk production, protein, lactose, or somatic cell count. Milk fat percentage was reduced from 3.39% in controls to 3.30, 3.04, and 2.98%, respectively, by the Ca-tFA diets and to 2.54% by the Ca-CLA diet. Milk fat yield (1.24 kg/d in controls) was decreased by 60, 130, and 190 g/d with increasing dose of Ca-tFA and by 290 g/d with the Ca-CLA supplement. Consistent with increased endogenous synthesis of cis-9-containing CLA from precursors provided by the Ca-tFA diets, total CLA were similar in milk of cows fed Ca-CLA or Ca-tFA. Compared with controls, the Ca-CLA diet increased trans-10, cis-12-18:2 yield in milk, without altering levels of trans-18:1 isomers. In contrast, yields of most trans-18:1 isomers were elevated in milk of cows fed Ca-tFA diets, whereas yields of trans-10, cis-12-18:2 remained similar to control values. We conclude that milk fat depression can occur without an increase in trans-10, cis-12-18:2 in milk and that other components, perhaps the trans-10-18:1 isomer, may be involved.

Note:

Related Files :

Related Content

More details

You may also be interested in