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
| Autor: | Martin P. Yurawecz, Kim M. Morehouse, D. Luchini, Joseph Sampugna, Uzi Moallem, Richard A. Erdman, L.S. Piperova, Beverly B. Teter |
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| Rok vydání: | 2004 |
| Předmět: |
Rumen
Animal feed Linoleic acid Palm Oil Linoleic Acid Random Allocation chemistry.chemical_compound Isomerism Lactation Genetics medicine Animals Plant Oils Dry matter Food science Lactose Dairy cattle chemistry.chemical_classification Dose-Response Relationship Drug food and beverages Trans Fatty Acids Animal Feed Lipids Dairying Milk medicine.anatomical_structure chemistry Dietary Supplements Animal Nutritional Physiological Phenomena Calcium Cattle Female Animal Science and Zoology Somatic cell count Food Science Polyunsaturated fatty acid |
| Zdroj: | Journal of Dairy Science. 87:3836-3844 |
| ISSN: | 0022-0302 |
| DOI: | 10.3168/jds.s0022-0302(04)73523-7 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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