L-tyrosine

1. L-tyrosine decreases DNA methylation in chickens (p < 0.05).

   “L-tyrosine also upregulated the expression of key dopaminergic and reproductive signalling genes, with corresponding promoter hypomethylation (p < 0.05)”

   Animalsaged laying hens12 weeksfemalesn = 180

   Dietary L-Tyrosine Sustains Egg Production and Quality by Modulating Promoter CpG Methylation, Gene Expression, and Hormone Profiles in Reproductive Signalling Pathways of Aged Laying Hens

   Journal of animal physiology and animal nutrition·7 Jun 2026

More on DNA methylation

1. L-tyrosine decreases prolactin in chickens (p < 0.05).

   “Dietary L-tyrosine increased plasma DA and serum estradiol while reducing serum PRL (p < 0.05).”

   Animalsaged laying hensserum12 weeksfemalesn = 180

   Dietary L-Tyrosine Sustains Egg Production and Quality by Modulating Promoter CpG Methylation, Gene Expression, and Hormone Profiles in Reproductive Signalling Pathways of Aged Laying Hens

   Journal of animal physiology and animal nutrition·7 Jun 2026

More on Prolactin

1. L-tyrosine increases estradiol in chickens (p < 0.05).

   “Dietary L-tyrosine increased plasma DA and serum estradiol while reducing serum PRL (p < 0.05).”

   Animalsaged laying hensserum12 weeksfemalesn = 180

   Dietary L-Tyrosine Sustains Egg Production and Quality by Modulating Promoter CpG Methylation, Gene Expression, and Hormone Profiles in Reproductive Signalling Pathways of Aged Laying Hens

   Journal of animal physiology and animal nutrition·7 Jun 2026

More on Estradiol

1. L-tyrosine increases dopamine in chickens (p < 0.05).

   “Dietary L-tyrosine increased plasma DA and serum estradiol while reducing serum PRL (p < 0.05).”

   Animalsaged laying hensplasma12 weeksfemalesn = 180

   Dietary L-Tyrosine Sustains Egg Production and Quality by Modulating Promoter CpG Methylation, Gene Expression, and Hormone Profiles in Reproductive Signalling Pathways of Aged Laying Hens

   Journal of animal physiology and animal nutrition·7 Jun 2026

More on Dopamine

1. L-tyrosine increases hen-day egg production in chickens (p < 0.05).

   “Hens in the TYR1 group exhibited higher hen-day egg production, improved feed conversion ratio, and significantly greater eggshell weight, shell thickness, Haugh unit, yolk index, and albumen index than the control group (p < 0.05).”

   Animalsaged laying hens1 g/kg12 weeksfemalesn = 180

   Dietary L-Tyrosine Sustains Egg Production and Quality by Modulating Promoter CpG Methylation, Gene Expression, and Hormone Profiles in Reproductive Signalling Pathways of Aged Laying Hens

   Journal of animal physiology and animal nutrition·7 Jun 2026