Regulatory mechanisms of nutritional factors on melanin deposition in Taihe Silky Fowls

The black pigmentation trait in Taihe silky fowls results from melanin deposition produced by widely distributed melanocytes within their bodies. The degree of melanin deposition, termed melanization, not only determines their external characteristics but also critically influences their nutritional properties and medicinal value. Nutritionally, Taihe silky fowls with high melanization are rich in trace elements such as iron and zinc, along with various vitamins, conferring high nutritional value. Medicinally, according to traditional Chinese medicine theory, highly melanized Taihe silky fowls possess therapeutic effects including nourishing the liver and kidney, replenishing Qi, and enriching the blood. Specifically, they improve liver and kidney health, promote blood production and circulation, and enhance immune capacity. This paper comprehensively reviews the molecular mechanisms of melanin biosynthesis and deposition. It specifically analyzes how particular nutrients, including amino acids, vitamins, and minerals, regulate melanin deposition in Taihe silky fowls at the level of cellular pathways, while also discussing their appropriate dietary supplementation levels in production practices. The aim of this review is to deepen the understanding of the mechanisms underlying melanin trait formation in Taihe silky fowls and to provide theoretical support for the scientific optimization of their dietary nutritional formulations.