Dose-dependent effects of cannabidiol in drinking water on yolk fatty acid profile and hepatic expression of polyunsaturated fatty acids (PUFAs) -related genes in laying hens: insights into the cannabidiol (CBD) systemic and molecular mechanisms of action.

The present research evaluated the effect of water-soluble cannabidiol (CBD) emulsion on egg yolk fatty acid profile, liver health, and gene expression in laying hens. 180 Lohmann Brown Classic hens were divided into experimental groups, including a control group, a blank group (emulsifier only), and three groups receiving CBD. Cannabidiol was administered in drinking water for 15 weeks at doses of 20, 40, and 80 mg/kg body weight in group I, group II, and group III, respectively. The analysis indicated that the highest-dose CBD significantly increased yolk polyunsaturated fatty acids (PUFAs), particularly omega-3 and omega-6, as well as the serum HDL level. However, this was accompanied by downregulation of PPAR-γ expression. The histopathology of the liver did not show any differences among the groups, and tissue morphology remained normal without structural alterations. The expression of fatty acid desaturation genes, such as FADS1 and FADS2, remained stable, indicating preserved desaturation function and PUFAs biosynthesis. These results suggest that while the highest dose of CBD enhances lipid mobilization and yolk deposition, it simultaneously may affect PPAR-γ-mediated lipid pathways (e.g., adipogenic programming or lipid storage/transport) despite intact desaturation pathways. While hemp-derived products such as seeds and meals have been tested in poultry diets, the specific role of purified cannabidiol (CBD) in regulating lipid metabolism and liver health in laying hens has not been previously addressed. This is the first study to investigate the molecular impact of purified CBD on lipid metabolism and liver function in laying hens, explaining its potential as a functional feed additive in poultry nutrition.