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Targets and procedures for altering ruminant meat and milk lipids

Published online by Cambridge University Press:  28 February 2007

D. Demeyer  and
M. Doreau
D. Demeyer*
Affiliation:
Department of Animal Production and Department of Nutrition and Food Technology, University of Gent, Proefhoevestraat 10, 9090 Melle, Belgium
M. Doreau
Affiliation:
Ruminant Undernutrition Laboratory, Institut National de la Recherche Agronomique, Theix, 63122 Saint-Genès-Champanelle, France
*
*Corresponding Author: Professor D. Demeyer, fax +32 9 264 9099, email Daniel.Demeyer@mug.ac.uk
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Abstract

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Beef and dairy products suffer from a negative health image, related to the nature of their lipid fraction. Rumen lipid metabolism involves the presence of saturated lipids in ruminant tissues. Lipolysis, fatty acid biohydrogenation and formation of microbial fatty acids in the rumen and their effects on rumen outflow of fatty acids are discussed. Special emphasis is given to the formation of trans-fatty acids and the possibilities of decreasing biohydrogenation. Small differences in intestinal digestibilities of fatty acids are mentioned, followed by a discussion on transfer of absorbed fatty acids into milk and adipose tissue lipids. The preferential retention of polyunsaturated fatty acids as well as the balance between synthesis and incorporation of fatty acids in tissues is described. Dietary means for the modification of milk fat are listed, with special emphasis on the possibilities for enrichment in polyunsaturated fatty acids and the presence of conjugated linoleic acids. A description of the nature and development of fat depots in beef cattle is followed by a discussion of breed, conformation and feed effects on adipose tissue distribution and fatty acid composition. Special emphasis is given to the very lean Belgian Blue double-muscled breed. The review ends with a consideration of the limits to the modification of ruminant fats, involving considerations of consumer acceptance as well as animal welfare and environmental effects.

Keywords

Beef and dairy productsRuminant fatsPolyunsaturated fatty acidsBelgian Blue double-muscled cattle
Type
Symposium on ‘Food technology: can it alter the functionality of nutrients’
Information
Proceedings of the Nutrition Society , Volume 58 , Issue 3 , August 1999 , pp. 593 - 607
Copyright
Copyright © The Nutrition Society 1999

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