Feather’s RNA: A Non-Invasive Approach for Transcriptomic Profiling in Live Chickens

This study investigated the feasibility of using blood feather transcriptomics to detect sex-differences and gene response to physiological changes in chickens. The identification of molecular markers associated with metabolism in poultry typically requires invasive sampling of tissues, such as liver. Feathers represent a promising non-invasive biological source of RNA: the quill pulp of growing feathers contains living cells capable of active transcription. Growing feathers were collected from 150-day-old male and female chickens (Bionda Piemontese, slow-growing breed) raised under a free-range system and fed two finishing diets differing in lipid content: low-lipid (LL, ether extract 3.6%) and high-lipid (HL, ether extract 9.3%). RNA was extracted from quill pulp and subjected to whole RNA-Seq analy-sis. Differential gene expression and functional enrichment analyses were performed us-ing the RaNA-Seq platform. A total of 17,360 transcripts were detected and used for downstream analyses. Across all individuals, three genes associated with ether lipid metabolism (PLA2G10, PLA2G4F, and ENPP6) were consistently upregulated in chickens fed the HL diet. Sex-specific responses were also observed. In roosters, HL feeding significantly affected genes involved in lipid transport and metabolic regulation within the PPAR signaling pathway, including APOA1 and SLC27A4. In contrast, hens showed differential expression primarily in pathways related to apelin signaling, extracellular matrix remodeling, and cardiovascular function rather than classical lipid metabolism pathways. These findings demonstrate differential responses to dietary treatments between males and females and reveal metabolic differences, confirming the need for sex-specific anal-yses in this local breed. In conclusion, feather RNA-Seq successfully captured diet-induced molecular responses and revealed sex-specific metabolic adaptations to dietary lipid levels. This study demon-strates that quill pulp represents a practical and ethically favorable alternative to tradi-tional tissue sampling and may support future nutrigenomic and genetic improvement studies. The findings support the development of non-invasive biomarkers applicable to genetic selection and precision nutrition, ultimately supporting more sustainable poultry production.