
01/16/2025
Did you know that every gray horse is genetically another color that turned to gray over time? They can be any color – black, bay, roan, buckskin, etc. The gray mare in the photo is genetically red (chestnut/sorrel) with the gray gene and her foal is black turning gray.
🧬Gray foals are usually born much darker than other foals. For example, a black foal that will turn gray is often born solid black with dark legs, while a black foal with no gray is often born a grayish color with lighter legs.
🧬The gray gene is dominant, which means it doesn’t “skip” generations. A horse that has the gray gene will turn gray and have a 50% chance of passing it to their offspring (or a 100% chance, if they have two copies of gray).
🧬The speed at which they gray varies and is also linked to their risk for melanoma, a type of skin cancer. Horses that turn gray more quickly have a higher risk for melanoma incidence. Until recently, we weren’t sure what affected the speed of graying or the risk for melanomas. However, new research explains that there are actually two types of gray (two different alleles, G2 and G3). Horses with G2 are slower graying and have a lower melanoma risk, while G3 horses are faster graying and have a higher melanoma risk.
Links:
https://vgl.ucdavis.edu/test/gray_copy_number
https://www.nature.com/articles/s41467-024-51898-2
Do you have a gray horse? Post a picture in the comments! 🙂