Makes up the majority of the white line?

• A. Keratin
• B. Horn cell matrix
• C. Laminar tissue
• D. Nervous tissue

Answer: (B)

The white line is primarily made of horn cell matrix—the dense, cornified tissue produced by the epidermal horn cells that forms the hard keratin of the hoof. The white line isn’t just keratin as a protein, nor is it nervous tissue or laminar tissue; it represents the organized horn tissue at the junction between the hoof wall and the sole. This horn cell matrix accounts for the distinct, pale seam seen at the hoof margin.