Effect of Curcumin Supplementation in Laying Hen Diet on Performance, Yolk Fatty Acid Composition and Elovl Genes

The study was designed to determine the effects of different levels of curcumin supplementation in the diets of laying hens on performance, egg quality criteria, yolk fatty acid composition, and the identification, characterization, and mRNA transcription of the elongation of very long chain fatty acids (ELOVL) genes. In the experimental design, Hy-Line Brown commercial laying hens were selected for a feeding trial lasting ten weeks. During this period, the hens were fed diets supplemented with curcumin at 0, 100, 200, 300, and 400 mg/kg. Performance characteristics, egg quality criteria and yolk fatty acid compositionwere determined by measurements made during the experimental period. At the end of the experiment, the expression levels of ELOVL genes were determined in liver tissue samples. At the end of the experiment, it was found that 100 mg/kg curcumin significantly (p < 0.05) increased Haugh unit, while 300 mg/kg significantly (p < 0.05) increased egg weight. Addition of 100 mg/kg curcumin to the diet increased the ratio of linoleic acid and linolenic acid, while 200 mg/kg curcumin increased the ratio of docosahexaenoic acid (DHA) to the highest level. In addition, it was observed that 100 mg/kg curcumin significantly increased ELOVL6 and ELOVL7 gene expression levels, and 400 mg/kg significantly increased ELOVL5 gene expression levels. These findings add to the further evidence suggesting that dietary curcumin can modulate ELOVL mRNA transcription in chickens. As a result, it was concluded that especially 100 mg/kg curcumin level would be suitable for use in the diet of laying hens.