Trans and conjugated fatty acids in milk from cows and goats consuming pasture or receiving vegetable oils or seeds
<p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">This review summarises the effects of nutritional factors on fat content, different isomers of <em>trans</em>18:1 and conjugated<span style="font: 12.0px Helvetica;"> </span>&l...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Taylor & Francis Group
2010-01-01
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| Series: | Italian Journal of Animal Science |
| Subjects: | |
| Online Access: | http://www.aspajournal.it/index.php/ijas/article/view/283 |
| Summary: | <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">This review summarises the effects of nutritional factors on fat content, different isomers of <em>trans</em>18:1 and conjugated<span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">linoleic acids (CLA) in milk fat from dairy cows and goats. Main dietary factors taken into account are the nature of for-<span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">ages and pasture, and supplementation with oil seeds, vegetable or marine oils. The effects of interactions between the<span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">nature of forages and lipid supplements in cows or goats are reviewed with particular attention. Lipid supplements could<span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">highly increase mean <em>trans</em>-vaccenic acid (TVA) and <em>cis</em>-9, <em>trans</em>-11 CLA content in ruminant milk fat, and interact with<span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">the quantity of concentrate in the diet or the type of preserved forage. Vegetable or fish oil supplementation increased<span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">milk <em>cis</em>-9, <em>trans</em>-11 CLA up to 4% (in total milk fatty acids (FA)). The content of copper or vitamin E in the diet could<span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">modify the milk percentage of TVA and <em>cis</em>-9, <em>trans</em>-11 CLA. Other isomers of <em>trans</em>-18:1 (e.g. <em>trans</em>-10) and CLA (<em>e. g.</em><span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;"><em>cis</em>-11, <em>trans</em>-13 or <em>trans</em>-11, <em>trans</em>-13 or <em>trans</em>-7, <em>cis</em>-9 or <em>cis</em>-9, <em>cis</em>-11 CLA) may be manipulated by diet composition.<span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">However, further studies are needed to establish their responses to different feeding strategies. The <em>trans</em>-10, <em>cis</em>-12 CLA<span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">in percentage in milk fat was always lower than 0.15% of total FA. The proportions of different <em>trans</em>-18:1 isomers in<span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">milk fat are similar in caprine and bovine species. Recent studies showed that the CLA content of goat milk fat was sim-<span style="font: 12.0px Helvetica;"> </span></p> <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 8.0px Verdana;">ilar to values (0.4 - 0.9% and up to 4% for winter and lipid-supplemented diets, respectively) observed in the cow.<span style="font: 12.0px Helvetica;"> </span></p><div><span style="font-family: Helvetica, Arial, Helvetica, sans-serif; font-size: small;"><span style="font-size: 12px;"><br /></span></span></div> |
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| ISSN: | 1594-4077 1828-051X |