, Volume 36, Issue 11, pp 1217–1222

Incorporation of dietary linoleic and conjugated linoleic acids and related effects on eggs of laying hens

  • Klaus Schäfer
  • Klaus Männer
  • Angelos Sagredos
  • Klaus Eder
  • Ortwin Simon

DOI: 10.1007/s11745-001-0835-0

Cite this article as:
Schäfer, K., Männer, K., Sagredos, A. et al. Lipids (2001) 36: 1217. doi:10.1007/s11745-001-0835-0


In the present study, laying hens received 29 g per kg diet of a preparation containing either 70% linoleic acid (LA) or approximately the same amount of conjugated linoleic acid (CLA) in the control and experimental treatments, respectively. The CLA preparation consisted predominantly of cis-9,trans-11 and trans-10,cis-12 fatty acid isomers as free fatty acids in a ratio of 1∶1. The diets were fed for 8 wk to determine the effect of dietary CLA on quality characteristics of eggs. In addition, the fatty acid composition of liver and heart was analyzed. Performance parameters (egg weight, feed efficiency) were not significantly affected by feeding the diets supplemented with CLA. The overall amount of CLA that was incorporated into yolk was 7.95 g CLA/100 g total fatty acids, or approximately 400 mg CLA/egg. The transfer efficiency of the cis-9,trans-11 isomer was higher than that of the trans-10,cis-12 isomer; however, the transfer rate of CLA isomers into yolk and tissues was significantly lower than that of linoleic acid. Dietary CLA increased the concentration of saturated fatty acids in yolk and tissues at the expense of monounsaturated fatty acids. The proportions of myristic, palmitic, and stearic acids in yolk lipids were also changed by dietary CLA. Additionally, long-chain polyunsaturated fatty acids (arachidonic acid and docosahexaenoic acid) were decreased without changing the balance of the n−6/n−3 ratio in egg yolk. The inclusion of CLA in layer diets altered the shape of the yolk and various egg parameters (albumen height, foam index, and yolk index). The results of this study indicate that CLA induces various changes in lipid and fatty acid metabolism of laying hens and affects quality characteristics of eggs.



conjugated linoleic acid


fatty acid methyl ester


linoleic acid


low density lipoprotein


monounsaturated fatty acids


polyunsaturated fatty acids


saturated fatty acids



Copyright information

© AOCS Press 2001

Authors and Affiliations

  • Klaus Schäfer
    • 3
  • Klaus Männer
    • 3
  • Angelos Sagredos
    • 1
  • Klaus Eder
    • 2
  • Ortwin Simon
    • 3
  1. 1.TrocoCell Research and Trade GmbHHamburgGermany
  2. 2.Institut für ErnährungswissenschaftenMartin-Luther-Universität HalleHalle (Saale)Germany
  3. 3.Institut für TierernährungFreie Universität BerlinBerlinGermany