title: Effects of conjugated linoleic acid on the performance of laying hens, lipid composition of egg yolk, egg flavor, and serum components.
abstract: OBJECTIVE
  This experiment investigated the effects of dietary supplementation with conjugated linoleic acid (CLA) on the serum components, laying hen productivity, lipid composition of egg yolk, egg flavor and egg quality.
  
  
  METHODS
  Healthy 28-week-old Hy-Line white laying hens (n = 480) were divided randomly into 4 groups, 6 replicates/group, 20 birds/replicate. The 30-day experimental diets included 0% (control), 0.4%, 0.8%, and 1.6% CLA. Some serum indices of the birds, and egg production, quality, fatty acid composition, egg quality were measured.
  
  
  RESULTS
  The dietary supplementation with 0.4%, 0.8%, and 1.6% CLA did not significantly affect the laying rate and feed intake, as well as calcium ion and phosphorus ion concentration in serum (p>0.05). However, the CLA had significantly increased the strength of eggshell, decreased the odor, flavor, and taste of egg yolk, deepened the color of egg yolk, increased saturated fatty acids and polyunsaturated fatty acids, and reduced the monounsaturated fatty acids (p<0.05). On the other hand, the dietary supplementation with 1.6% CLA had significant effects on feed/gain, and improved serum hormones. Dietary supplementation with 0.4% and 0.8% CLA can significantly enhance the activity of alkaline phosphates.
  
  
  CONCLUSIONS
  CLA has no effect on production performance, but does enhance the lipid content of the egg yolk and the strength of the eggshell.
authors.affiliation: Poultry Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250023, China.
authors.forename: Xuelan
authors.initials: X
authors.lastname: Liu
authors.affiliation: Poultry Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250023, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Poultry Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250023, China.
authors.forename: Peipei
authors.initials: P
authors.lastname: Yan
authors.affiliation: Poultry Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250023, China.
authors.forename: Tianhong
authors.initials: T
authors.lastname: Shi
authors.affiliation: Poultry Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250023, China.
authors.forename: Xiangfa
authors.initials: X
authors.lastname: Wei
keywords: Conjugated Linoleic Acid; Dietary Supplementation; Feed Efficiency; Laying Hen; Lipid Composition