Abstract
Steroid hormones are often used in animal agriculture but are currently banned for use in domesticated fowl because residual hormones could be present in eggs for human consumption. Egg samples from eight common commercial poultry layer breeds (Hy-Line W-36, Hy-Line Brown, ISA-White, ISA-Brown, Lohnmann Ultra-Lite, Lohnmann-Brown, Hisex White, Hisex Brown) in Taiwan were screened for a combination of 15 natural and synthetic steroid hormones by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for consumer assurance. Only natural hormones such as progesterone, 4-androstene-3,17-dione, and testosterone were detected. Regarding each breed, the interaction effect (age × shell color), main effect (age or shell color), and blocking effect (lighting system) were further analyzed by using 2 × 2 factorial arrangement of treatment in a randomized block design. We also discovered associations between yolk steroid hormone levels and laying hen age, as well as lighting conditions. Additionally, we found a correlation between hormone levels and eggshell color, suggesting a potential role in brown pigmentation. Ultimately, we concluded that detectable steroid hormone levels in eggs were not a consumer health risk. Furthermore, these data provide empirical hormone concentrations in various types of commercial layer breeds for future research.