Regulation of Goat Milk Protein Synthesis: Genetic Architecture, Signalling Pathways, and Omics Insights.

Milk protein synthesis in goats is governed by multilevel regulatory mechanisms coordinating genetic, hormonal, nutritional, and cellular signals. Despite growing interest in goat milk proteins due to their distinctive nutritional properties, digestibility, and reduced allergenicity, their regulatory basis remains less characterised than other dairy species. This review integrates current knowledge on goat milk protein composition, genetic polymorphism, and molecular regulation, summarising structural and functional characteristics of caseins, whey proteins, and minor bioactive proteins. It examines how polymorphisms and haplotypes contribute to breed-specific variation in milk yield, composition, and physicochemical properties, highlighting JAK-STAT and mTOR signalling pathways' central roles in integrating hormonal and nutritional signals that control transcription and translation. Evidence from GWAS, QTL analyses, transcriptomics, proteomics, and epigenetic studies outline the genomic architecture and stage-specific regulation of milk protein synthesis, while highlighting knowledge gaps and research opportunities. By integrating genomic, transcriptomic, proteomic, and epigenetic evidence, this review highlights candidate regulatory variants and molecular pathways underlying milk protein synthesis, providing a framework for functional validation, precision breeding, and the development of high-value goat dairy products.